Best Free Firewall Protection


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Firewalls help monitor your system's communications between your network and the Internet, to help detect and prevent intrusions and attacks. They are particularly useful for controlling the activities of Internet facing applications.

Firewall products are arguably one of most cumbersome and has a reputation of causing user angst - to find a suitable product that meets individual users' needs may involve a process of trial and error. A good firewall should be able to protect to user at a near-perfect level, while not being too intrusive or complicated to handle. The type of user may very well determine the funcitonality or feature set that is necessary for each individual user. In this article, we give you a selection of some of the best free firewall software, in our opinion, that is available. Our reviews and recommendations are made taking into consideration both editors' and site visitors' experience, opinions, and comments. As always, if you have more to share we would love to hear from you. Please refer to the comments section at the bottom of this page.

Firewalls come in two flavours; software based and hardware based. Software based firewalls (which is what we will cover in this article) reside on your machine, running in the background in order to keep a watch on things. To avoid potential conflicts only install one (third-party) software firewall. In order to achieve the best combination of protection, we would strongly suggest to use a hardware firewall (such as a router) in conjunction with a software firewall. Modern routers usually have a built-in firewall, helping to filter out content before your machine; consult your router documentation for more details.

Basic firewall protection is critical for securing your PC. Simple firewalls (like the default Windows firewall) limit access to your system and personal information, and silently protect you from inbound threats. We review basic third-party firewalls as well as the built in Windows firewall, and look at features such as monitoring programs that request outgoing Internet connections (we call this "outbound protection").

Basic firewalls generally only have limited protection;proactive firewalls offer more extended protection, including HIPS or program monitoring (HIPS Explained), and watch for malicious behavior before malware gets a chance to take control of your PC or turn it into a botnet drone. They seek to achieve stronger "2-way" protection, preventing programs from broadcasting your personal information to the Internet. The downside of such firewalls are that it may be harder to use and/or require more memory consumption. Also, there is a greater risk of HIPS software causing conflicts, errors, or otherwise cause other issues with your PC.

Some kinds of malware are best detected by their behavior, so a proactive firewall (or firewall/HIPS combo) is a solid second layer of protection next to your antivirus program. It is an excellent option for high risk users. However, it's plausible to argue that a good resident antivirus will stop some malicious threats before they get a chance to make it to the Internet anyway. Many of the top antivirus programs are starting to provide behavioral blocking and extended scanning of network activity. Nevertheless, it is important to use basic or proactive firewall protection, antivirus software for active protection, and safe practices in order to minimize the risk of malware on your PC.

You can "upgrade" (for free!) your security by reading the documentation and learning about proactive firewalls or HIPS programs, or using other protection like least-privileged user accounts and/or Sandboxie or GeSWall. This information, and more, is available on various parts of our website.

Review Index

Additional Tips/Precautions

  • Before installing new resident security products, including antivirus and firewall programs, consider making a full drive image. By creating a full drive image you are able to restore your entire computer back to a previous state in the event your system becomes completely unresponsive. Drive imaging allows you to recover from unintentional conflicts as well as severe malware infections. Everyone's system is unique and may have old, latent drivers that may be incompatible with whatever you are installing, causing problems with your system. Newer versions of Windows have a built in "Complete PC Backup and Restore" feature, or you can use a free drive imaging program
  • To cleanly uninstall your (third-party) firewall before installing a new one, you may consider using ZSoft Uninstaller to analyze before and after the installation. If you haven't used it on your current firewall, try Revo Uninstaller (or other vendor or Windows uninstaller), check for leftover services and drivers with Autoruns, and restart your computer.


Basic Firewalls


The built-in Windows firewall is a common choice since it passes all inbound tests (both stealth and open port) and doesn't have many popup alerts. It doesn't require a separate software installation, as it comes built-in with modern versions of Windows. Therefore, it is not likely to conflict with your other programs. And many average users may not reliably handle the popup alerts of the more complex firewalls on the market, especially at their max settings. Newer versions of Windows also feature an updated, improved version of Windows firewall than prior versions of Windows.

If you scan clean for malware, don't want/need the additional features of a third-party firewall, and are a relatively low risk user, then the Windows firewall could be a practical and useful solution.

Alternatively, you can replace the Windows firewall with a basic third-party firewall for greater control of outbound protection and additional features. Most simple two-way firewalls ask you to allow or deny Internet access for unknown programs. Many also automatically allow trustworthy apps and remember your decisions to become silent over time. However, these software require additional configuration of settings, especially at the outset.


Basic Firewall Reviews

Windows has come with a built in firewall in its operating system ever since XP. The initial firewall that came with XP was simple, and only allowed protection from incoming traffic, by blocking any incoming connections not initiated by your computer. The firewall does provide excellent basic functionality while running seamlessly in the background. It does the same job as what a third party firewall should do; that is, blocking unwanted incoming connections from the internet. As each version of Windows may contain slight variants of the built in firewall, this review only encompasses a general overview of the built in firewall, without going into the specifics of each.

The Windows firewall is enabled by default on your Windows system. Therefore, unless you disabled it or installed another third party firewall, it should still be running if you have not changed the firewall settings. You can access the firewall interface from the Control Panel, and it is relatively straightforward. When there is a program that wants to receive incoming connections, you will receive a dialog box asking if you would like to allow it access. That’s really all there is to the basic functionality. All other incoming connections not originating from your system will be blocked by your firewall, without any intervention needed from the user. Simple to use, effective, and it comes built in right with Windows, eliminating the need for tinkering with additional installations.

Subsequent versions of Windows have seen an improved version of the firewall. Starting with Windows Vista, new features such as the ability to filter outgoing traffic, though in a more advanced view, are now available. The advanced version allows you to create advanced firewall rules, such as blocking certain programs from connecting to the internet. This advanced view can also be access via the control panel; however, it is not the most user friendly interface. As an alternative, you may want to consider using a third party tool such as Windows 10 Firewall control (discussed below) to complement the built in firewall.

Nevertheless, the built in Windows firewall is definitely one of, if not the most, convenient and efficient firewall available. It is very suitable for most users, especially the casual user who may not be as inclined or have advanced knowledge of their computer system. It is excellent at its job; it passes all tests and has proven to be a reliable firewall application. In addition, other third party firewalls run the possibility of causing conflicts or problems with your PC. With the built-in firewall, the chances of such problems occuring are significantly lower. The downside is that it does not provide the user with as great control as some other third party firewalls; however, such control may not be worth the additional effort, or even necessary, for most low risk or novice users.

Furthermore, it is also important to consider which version of Windows you are using. For example, the firewall in Windows XP is not as sophisticated as, for example, Windows 7. Therefore it may be more advisible to explore a third party firewall if you are using an earlier version of Windows, as opposed to the more recent releases. Suffice to say that if you are still running an even older version of Windows that does not have a built in firewall, you would need to consider one of the options below.



Windows 7 Firewall Control Windows 10 Firewall Control is a good choice to supplement the Windows built-in Firewall. Despite its name, the program is compatible with Windows XP and higher. The vendor offers multiple editions, in addition to its freeware edition. In a nutshell, Windows10FirewallControl allows the user to configure the Windows firewall to block or allow applications from connecting to the internet; it adds better outbound protection configuration to the built-in Firewall. It is based on the Windows Filtering Platform (which is what the built-in firewall is also based on), so unlike most other firewalls it does not install any third party kernel drivers. The user interface is clean and simple, reflecting what this program does (ie. block or allow application access - nothing more).

There are three modes a user can choose from; Normal, DisableAll, or EnableAll. DisableAll disables all applications regardless of program settings, while EnableAll allows all application access (essentially equivalent to switching off the firewall completely). Unless needing to test something specifically, the Normal Mode is the recommended one - applications/programs are allowed or denied access depending on the rules set.

Under the Normal Mode, when a program tries to access the internet for the first time (upon installation of W7 Firewall Control) a window pop-ups with information on what the application is, the publisher, etc (assuming default program settings). You can then allow or disallow access, either permanently or as a one-time basis. Selecting the former option will add the settings permanently to the Programs list, while with the latter option you will have to deal with the pop-up window again on the next launch.

In addition to the window pop-up for new programs, activities that take place (ie. blocked/allowed traffic, etc) are logged and shows up in the bottom right corner of your screen. Both the pop-up window and log activity notification dialogue can be turned on or off at the user's discretion.

That's basically all there is to it. It may get a bit annoying when you first starting using it, since you will have to define the initial rules for all your applications (ie. allow or disallow them); this includes everything from Internet Explorer to your antivirus program. Nevertheless, Windows10FirewallControl allows greater and easier control over the built-in firewall without installing additional kernel drivers on your computer.



ZoneAlarm Free Firewall  is a well-established inbound/outbound OS firewall solution suited for users of every level of experience. ZoneAlarm protects systems from intrusions as well as program access to the web. ZoneAlarm features an easy-to-understand user interface. Users can adjust security settings for their needs to allow for file/printer sharing, public networks, and even turn off the firewall if ever needed. Simple controls in the form of visual slide bars make setting up this firewall a snap. ZoneAlarm offers to help users setup initial program access with a first-run scan of installed software and allows/denies accordingly. However, this first scan does not always offer accurate access to programs.

Users will have to interact with this firewall for a time after installation to make sure programs needing LAN or internet access are granted proper permissions. Popups are very simple in format offering Deny, Accept, and a checkbox a user can check to make ZoneAlarm remember the decision. Novice users should be able to easily identify the name of the program asking for web access so they can make the appropriate decision.

The Program Control will allow users to set ZoneAlarm for Low, which is a learning mode and no OS firewall protection and limited popups. Or users can choose Medium, which will make programs ask for permission to access the trusted and internet zones. The high setting is not offered in the Free version of ZoneAlarm. The Smart Defense Advisor will help reduce popups by offering settings for programs asking for access, based on the decisions made by other users worldwide. Users can choose whether or not to participate in ZoneAlarm's community defense program. Users can set programs access manually at anytime by going to ZoneAlarm's Program Control and selecting Programs.

Internet Zone controls are divided into the Trusted Zone, used for the local network to share files, printers, etc., and the Internet Zone for communication to/from the web. A simple 3-position format allows users to choose from "No protection" (firewall is off), Medium (Allows file/printer sharing), and High (will allow users to connect to a network but will not allow anyone else to connect to your system). The medium setting is recommended for home networks with more than one system, and for users whose modem requires this setting. The high setting is most recommended for single-system web access (only one computer at home and modem does not require a home network setting), and for public areas such as cafes, restaurants, and hotels (etc.) with wifi.

ZoneAlarm Free offers basic two-way defense, stealth mode, and anti-phishing protection. Recent versions have been lighter on resources than previous versions. However, it lacks HIPS or program-to-program protection.

It is worth noting that there have been some negative comments about the latest version of the software, at least from the visitors on our site. Most notably, many features have been removed, and may be regarded as a step down from previous versions. Perhaps something you may want to take into account when choosing a firewall product.


Tinywall 2.0 TinyWall is a lightweight firewall solution that works with the built-in Windows Firewall. With no pop-ups to annoy the user, it can be an ideal set-and-forget solution. The installation package is very small, weighing in at just over 1 MB. Installation is a breeze, though there is no option for the user to select where to install the program. After installation, it starts running quietly in the background, as indicated by the tray icon. All the program features can be accessed by clicking once on the tray icon; there is no 'main window' interface. From the pop-up menu, the user can also view and select, among others, the operating mode, total network activity, adding application/process exceptions, and accessing the Firewall Settings dialog.

The Firewall Settings dialog is where the user can manage General settings, such as password protecting the application. An application exceptions section also allows the user to specify applications that are allowed to communicate with the network. There is also a 'Detect' feature where the program will try to detect known applications, or the user can elect to manually add applications. Furthermore, TinyWall is able to recognize associated processes with the same application. For example, if you have a program that has more than one process, adding the first process will result in the program also offering to whitelist the second related process as well. Needless to say this is very useful for those applications that have more than one process.

It should be noted that when adding an exception to the list, the default settings are 'Unrestricted UDP and TCP traffic'. Depending on the nature of the program it may be necessary to restrict it to 'Outgoing only' to offer maximum security.

The special exceptions tab allows the user to specify more advanced settings; specifically, allowing the user to select which system services to allow/block. It is recommended to leave it as is unless there's something you really want to change.

The maintenance tab rounds out the Settings dialog, allowing the user to import/export settings, check for updates manually, and a link to visit the vendor's webpage.

A small, lightweight firewall, TinyWall is a solid choice for those looking for a reliable, low-resource firewall program that does not interfere with the user's computer usage.



Firewalls with HIPS Protection


The following personal firewalls provide an advanced level of network and HIPS protection. Each firewall comes with default settings and, depending on the users' needs, may or may not require much adjustments.

It should be noted that firewall products in this section require more time to learn and configure, and are more complex to use than basic firewalls. There is also a higher risk of conflicts and problems arising on your system. Since firewalls are often praised for their security effectiveness at their max settings, users will likely have lower protection than mentioned by independent testing sources, such as Matousec, for practical day to day use. All of the product vendors seek to provide user friendly features, sometimes incorporating reduced levels of protection in their default settings by decreasing some HIPS monitoring. In other words, these firewalls may be more suitable for more advanced users, as well as those that are more "high risk".


Proactive Firewall Reviews

Comodo Firewall is a good choice for users seeking a full featured security suite. This latest release is suitable for both lightly-skilled users (who still must have knowledge of installed programs) and technically advanced users. Its robust and active HIPS, or application monitoring feature, called "Defense+", matches or exceeds the security performance of pay products. Comodo allows for much control and customization for the curious or the paranoid.

Comodo includes a "memory firewall" (against buffer overflow attacks) and a light sandbox component to limit the way unknown applications and new software installations affect your computer. The use of sandbox protection limits the negative effects of malware. It maintains a lengthy list of known safe applications, but if an unknown application attempts entry through the firewall, Comodo will deny the application and ask the user what to do. The new release contains user friendly features by default while allowing experienced users to maintain control over ports, protocols, and configurations.

During installation the user has three firewall installation options to choose from:  Firewall Only, and Firewall with Optimum or Maximum Proactive Defense (ie. the Defense+ feature; disabling it will cause Comodo to behave as a two-way firewall only, with no proactive/HIPS functionality). After installation Comodo automatically selects "Safe Mode", which generates numerous popup alerts for applications not in its trusted vendors list (you can browse this list to see if you trust the vendors: go to the Defense+ tab > "Common Tasks" > "View My Trusted Software Vendors"). When you answer "allow" and "remember your answer" to popup alerts for an application, Comodo creates a custom policy for it. Some of its policies are fairly liberal.

In the more liberal "Clean PC Mode", Defense+ automatically treats all applications on your drive as safe (but if any malware is currently hidden on your drive, it too would be considered safe). Applications still receive some minimal monitoring for Comodo's two protected lists ("my protected registry keys" and "my protected COM interfaces") and for running as an executable, or more/less monitoring depending on their custom policy. And new files get sent to a list of files "waiting for your review" in the "Summary" page. Files listed for review will be considered possibly unsafe and will provoke popup messages, as if in Safe Mode, until their custom policies are made.

Comodo limits the frequency of alerts by automatically treating some programs as safe and allowing some applications to access the Internet. You can additionally automate the behavior of Defense+ by one or more of these methods for treating applications as safe:

  • Have it "remember your answer" to all popup alerts when an application first runs, which works for some applications (because some custom policies set this way are close to "trusted" status). But if an application still nags you, click "More Options" in the alert and use the drop down box to select "trusted" or "blocked" (etc.), if available, or set an application to trusted manually ("Defense+" > "Advanced" > "Computer Security Policy" > "Edit..." > "Use a Predefined Policy"), which finally ceases popup alerts and most intrusion prevention for that application.
  • Add files to the lists of "My Own Safe Files" or "My Trusted Software Vendors" in the interface (see the "Defense+" tab), which is most helpful for "Safe Mode" or "Paranoid Mode".
  • Use the "Clean PC Mode" (right-click the tray icon and select it under the "Defense+ Security Level"). But make sure to scan and remove any malware first.

The following exclusive guides from Gizmo's Freeware also contain many useful information about Comodo's settings: How to Install Comodo, How to Tame Comodo Defense+ Without Disabling It, and MC's Mini Tutorial.



Private Firewall A former commercial product, Private Firewall is now unrestricted freeware. It is a proactive multi-layer security solution, offering behaviour blocking technology alongside standard firewall protection. Using Behavioral-based Monitoring, it features zero-hour virus, spyware, and malware protection, process and application security, and registry protection, just to name a few. It is definitely a feature-packed firewall/HIPS solution.

 While there is a decent help file available, the user interface can be a bit confusing and overwhelming. There are many configurable settings, and sorting through them may require some time. To help out with that there is a information menu on the right of each screen which explains what each section is for. Training mode allows all actions within a 180-second interval, which is ideal for installing or running programs for the first time. On the first run after installing however, Private Firewall still managed to disable Panda Cloud Antivirus, the antivirus software on my test system, even with Training mode activated. Adding Panda Cloud Antivirus to the allow list seemed to solve this issue.

It is also possible to set different security levels for the Internet and the Network. Various levels of protection (High, Low, and Custom) can be separately specified for Internet Access and Network Security (ie. file and printer sharing). This is useful for, say, when one needs to access the internet via a network they don't quite trust. In addition, there are three profiles you can choose: Home, Office, and Remote. You can set appropriate settings for each one and easily switch between them as needed; this is particulary useful for portable computers which connect to many different networks. Another useful feature is that it is possible to block all outbound email; simply click the 'Block Outbound Email' icon in the main user screen and all outbound email should be blocked.

Overall, Private Firewall is a very effective firewall; it ranks among the top products on Matousec. However, the graphic interface and usability is perhaps more suitable and tailored for the more advanced users. Beginner computer users may want to consider another firewall instead, but if you are comfortable with the basics of Windows & firewall software, you should definitely consider Private Firewall.



Both types of firewalls (basic and HIPS/proactive) both have their benefits and drawbacks. While HIPS software do offer greater protection and control of your machine, it naturally requires more user interaction and resources, making such software not the easiest to use. There are more settings to configure and it is more complex to use than the basic firewalls.

On the contrary, basic firewalls are generally simpler to use and may be easier for the user to adjust and learn how to use it. Comparatively, they do not offer as much protection as HIPS software; for example, they cannot detect suspiciously acting software behaviour, as it primarily filters incoming and outgoing internet traffic.

If you are an advanced computer user and/or are a "high risk" user, then the increased complexity of a HIPS firewall may be the best option for you, as it offers you the maximum protection available (in this regard). However, for most average users who use their computer for regular day to day use, a basic firewall is probably more than adequate. For these latter parties, a HIPS firewall may simply be going overboard as the increased features, complexity, and configurations are unnecessary.


Other/Unsupported Firewalls

The following firewalls are now unsupported by their vendors. This means they have been discontinued and/or are no longer offered by the software publisher. While they may still be available for download, they may contain undocumented bugs or stability/security issues that will not be addressed. These reviews are archived for information purposes only. Unless you run an older Windows system with no other current firewall programs available, we would suggest using another program that is currently active.


Online Armor FirewallOnline Armor Free's HIPS feature is mostly in its "Program Guard". It has a feature called "run safer" that allows you to selectively set risky applications (web browsers, office software, readers/viewers, instant messengers, email or news programs, multimedia software, download managers, etc.) to run as if under a limited user account (go to "Programs" tab > uncheck "Hide Trusted" > highlight a program and click "Run Safer"). It minimizes popup alerts over time with its automatic list of safe programs, your on-demand scans with its safety check wizard, and your responses to popup alerts -- especially in cases where you tell it to remember your decisions and have it treat programs as trustworthy.

Run the wizard and have it search your PC for known programs to allow/block/ask. In this case, Online Armor relies on you to respond to alerts for unknown programs. For the curious or paranoid user, it uses excellent popup messages when it automatically allows a program to connect online and, optionally, when it automatically trusts a program/process to run (these alerts don't require user action and they can be enabled/disabled in the interface with "Options" > "Firewall", and "Programs" > "Options"). For example, I noticed a message when it auto trusted a key logger test, but after I set the tester to untrusted, it gave very informative and detailed security alerts (and then it passed the test and logged the tester in the interface under the "Key Logger" tab, but it only logged the key logger after the test was untrusted). You can even close both its tray tools from its right-click context menu. They are not needed for the firewall and HIPS components to continue running and protecting.

AVS FirewallAVS Firewall differs from other regular ones in that it comes with additional protection modules; namely a registry defender, a banner blocker, and parental control options – it is something like a suite. The firewall itself does not have as many configurable options as some of the firewalls listed on this page, but the standard selections are still there – off, which turns off the firewall; custom, which allows you to set your own connection rules; and high, which blocks all connections.

Each section of the program is displayed clearly; navigation is through the menu on the left. Alerts are generally clear and straightforward, as is configuration.

The registry defender protects the registry from being modified, with the option of only protecting select categories. The parental control limits the list of websites that can be accessed, but you must manually add each website to be trusted, ie. You cannot block specific websites; you can only allow certain websites. The anti-banner component blocks undesirable web page content including ads, flash banners, pop-ups and the like. All three of these additional modules can be disabled independently as desired. AVS Firewall also comes with a monitoring utility so you can check the size of network traffic which is sent and received by each application.

During installation of this firewall, the installer automatically installs the AVS Software Browser; there is no option to opt-out of installing this, but the program can be removed separately after installation with no effect on the actual firewall program. The installer also has a pre-checked option to install AVS Registry Cleaner, and it is recommended that it is unchecked so the installer does not install it. Therefore, while the software has some additional features not found in your everyday firewall program, most of those features can be found in other third party programs.

Outpost Screenshots Outpost Firewall Free by Agnitum software technology is a good choice for users who want highly flexible protection without sacrificing usability. It appears to be built with average users in mind, judging by the care taken to simplify alert messages and make it easy to adjust intrusion prevention (or HIPS) monitoring. For example, it remembers your responses to popup alerts without the need to set "trusted" rules (like in Comodo/Online Armor), and like Online Armor it notifies you when it automatically allows an application to access the Internet (especially helpful during the learning phase).

The free version lacks many extras of the pay version, however, such as automatic updates and the ability to break active connections. The HIPS component is called "Host Protection" in the interface. It provides four default levels of protection, which can be easily set with a slider and additionally customized item by item by advanced users. The default "optimal" setting only monitors the "most dangerous activities" (such as memory injections, driver loads, and a healthy list of system critical features -- auto starts, shell extensions, and internet settings) instead of all program activities. But these "optimal" settings lack protection from keyloggers, direct disk accessing, DNS API request monitoring, etc. You can check the types of reduced monitoring in "Settings..." > "Host Protection" > "Customize...".

Agnitum has now been acquired by Yandex. As a result, Agnitum has discontinued support and sales of the Outpost product line.


Other Unsupported Firewalls for Windows 95-2000


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Quick Selection Guide - Basic Firewalls

Windows Built in Firewall

Gizmo's Freeware award as the best product in its class!

Runs as a stand-alone program on a user's computer
Built in to Windows, no separate installation needed, simple and easy to use, effective, passes all tests, no nagging or annoying pop ups, runs seamlessly and quietly in the background, significant improvements since initial version in XP. Likely suitable for most day to day use.
Primarily incoming connecting protection only. Advanced user interface is not user friend - this interface may not be suitable for beginner users. Would be very beneficial complemented by a third party tool such as Windows10 Firewall Control. Windows XP's version is very basic and lacks any outgoing protection. May not provide adequate protection for "high risk" users
Built into Windows
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.
Product is built into Windows XP and higher, not available for separate download
Windows XP or higher


Runs as a stand-alone program on a user's computer
Lightweight basic firewall; simple yet effective. Non-intrusive program with no pop-ups. Ability to recognize associated processes when whitelisting programs. This program could be a good choice for those not familar with computers, as it does not require advanced knowledge to use.
No user dialog; everything is accessed from the pop-up menu. Not necessarily a bad thing, but may be different compared to what most are used to. Cannot select where to install the program. Requires .NET framework
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.

Windows 10 Firewall Control

Runs as a stand-alone program on a user's computer
Simple and effective; uses Window's built-in firewall platform so no third party kernel drivers are needed. Very small footprint. Three modes to choose from (Normal, EnableAll or DisableAll). Great for complementing Windows' built-in firewall
May be a bit annoying to use at first since the user must configure the initial rules for all their applications; no training mode. The dialog box that pops up to allow/disallow a particular program has a lot of information, some of which may not be too user friendly to beginner computer users. Online manual could be more comprehensive.
1.43 MB
32 and 64 bit versions available
Feature limited freeware
A portable version of this product is available from the developer.
Despite its name, this program works with Windows XP and higher
Windows 10 / 8 / 7 / Vista / XP/ Server 2003

ZoneAlarm Free Firewall

Runs as a stand-alone program on a user's computer
Solid inbound firewall, stealth mode, user friendly, customizable settings, anti-phishing protection, and hosts file lock.
Inadequate HIPS or program monitoring protection. No High setting for program access in Free version. In spite of available automatic update option, updates almost always must be performed manually. Help file designed for commercial version.
32 bit but 64 bit compatible
Free for private use only
There is no portable version of this product available.
To learn more visit its service and support page
Windows XP SP3 (32-bit), Vista SP2, 7, 8, 8.1, 10. Requires 2 GB RAM, 2 GHz+ CPU, 1.5GB disk space)


Quick Selection Guide - Firewalls with HIPS


Runs as a stand-alone program on a user's computer
Effective proactive security and stealth, one of the lightest of all tested firewalls on memory, simple setup (no nags or ads!). Easily choose between 3 network profiles. Has a unique "email/system anomaly detection" feature, which trains over 7 days by default. Quick to respond to queries / feature requests.
No automatic installation mode (but it has a training mode in "Settings" > "Advanced"). The tray icon flashes for log events instead of network activity per se. Program may be more suitable for advanced users due to the complex user interface and features. Program is still supported, however there appears to be no active development or updates currently.
32 bit but 64 bit compatible
Unrestricted freeware
There is no portable version of this product available.
Additional Features of Interest (as Found in its Interface): Built-in help and tips. Auto trusts safe vendors. Able to block outbound email automatically. Network options for experts, with three default settings to modify (Home, Public, Work). To learn more visit its feature list and online support (change log, user guide, & tutorials).
Windows 10, 8 / 8.1, 7, Vista & XP

Comodo Firewall

Runs as a stand-alone program on a user's computer
Its Defense+ HIPS performance exceeds commercial products and leads the class, it includes a "memory firewall" feature, and it allows you to quickly switch between Defense+ security modes and configurations. Includes automatic updates. Installation can automatically configure your PC to use the Comodo SecureDNS (but you can do this without installing CIS).
No built-in help. Despite not installing the AV component, the AV files are still placed in the Comodo program folder. Possible problems when uninstalling program; remants of the program are sometimes left on the computer
88 MB
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.
Additional Features of Interest (as Found in its Interface): Installation mode/training mode, auto updating, built-in help and tips, parental control with password protection, extra themes and languages, and a stealth ports wizard. Purges old or unused firewall/Defense+ policies or unused files (safe files, files waiting for review, etc.). Displays balloon messages for instant logging events. To learn more visit its forum, online help, and/or release notes.
Windows XP (SP2), Vista, Windows 7 - 512 MB RAM, 400 MB disk space

Online Armor Free

Runs as a stand-alone program on a user's computer
Excellent proactive security performance. Includes a "run safer" feature to reduce rights for specific risky applications, and the ability to monitor key logger activity and host files. It handles the installation of new programs better than some other tested products.
It doesn't have automatic updates or a built-in help. It's mandatory to enter an email during installation, and it has a pre-checked option to send it anonymous information. May have problems installing unless all remnants of similar programs have been removed from the receiving computer. Product is no longer supported by the vendor.
30 MB
32 bit but 64 bit compatible
Free for private use only
There is no portable version of this product available.

64-bit version only for Windows 7; XP 64bit and Vista 64bit are not supported Additional Features of Interest (as Found in its Interface): Set passwords, protect programs (right-click > "Advanced options"), key Loggers tab/Hosts tab, and multi desktop support. To learn more visit its forum, and blog.

Windows XP (32-bit), Vista (32-bit), 7; 512MB Ram, 50MB Disk space

Outpost Firewall Free

Runs as a stand-alone program on a user's computer
Proactive security (at max settings) compares with Online Armor. Highly flexible protection, simplified alert messages, and includes a full screen mode.
It fails tests for protection against malicious logouts or system shutdowns. The free version lacks automatic updates and the ability to break active connections. No longer supported by its vendor
16.63 MB; 98.81 MB for Security Suite
32 and 64 bit versions available
Feature limited freeware
There is no portable version of this product available.

Newer versions and 64-bit version are part of the Outpost Free Security Suite - includes additional software components which may conflict with existing software. 64-bit version (98.81 MB v7.1) available here: *Warning: Downloads from Cnet ( now require the use of a proprietary installer. Reduced HIPS monitoring (lacking anti-key logger protection for example) Additional Features of Interest (as Found in its Interface): Built-in "Help", full screen mode or entertainment mode.

Windows 7, Vista, XP - 450 MHz CPU, 256 MB RAM, 200 MB free disk space


Have Your Say

Your opinion matters! If you've used one of these firewall software before, and/or know of another outstanding freeware firewall, let us know in the comments section below. Alternatively, for a more comprehensive discussion, visit our forum.



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There is now way to block a range of IP's with PrivateFirewall, such a shame.

I would like to see Binisoft Windows Firewall Control tested. Online Armor is now in the beta phase of version 7. Version 6 has been out since a year or so. Sphynx Windows 7 Firewall Control is at version 5, version 6 is in beta testing. Maybe the tests can be update (OA 6, W7FC 5, BiniSoft).

Binisoft Firewall Control looks like a crippleware. A basic feature like notification for outgoing blocking, is available only for registered users who donate. That's quite a crippleware. There are better products available for free.
Agreed with Anupam. Unless a product has a version listed as "freeware" it won't be reviewed here. Even so, if the freeware version is considered to be crippled it won't be included either. MC - Site Manager.

Can you please till me if "Comodo Firewall" is still the best choice as free firewall software or not, i am asking because in your review i noticed that you rated "PrivateFirewall" with 4.5 stars and "Comodo Firewall" with 4, so i want to know if "PrivateFirewall" is the best choice now or not, or it is still "Comodo Firewall"?

I follow your review for my choice so i want to know which is the best now.

And thank you so much for your review.

Been running Comodo for years now and can't complain. However recently I have encounters issues when running Comodo 6 with Avast 7. When I started my PC (Win 7 64bit) Avast woulkd load but sometimes Comodo would not (about 33% of the time). Until Comodo loaded (i.e. the tray icon appeared) I was unable to browse the internet, email and software updates (well AVAST update) worked fine but internet browsing would not. Tried the various solutions on both the Comodo and AVAST forums, added both programs as exceptions to each other, disable the behavior blocker on AVAST, then swapped and disabled Comodo's instead, then turned it off on both, none of it solved the problem.
I have run the AVAST & Comodo combination for years and this problem only occurred when both were updated to their newest versions. I have also had this problem on multiple computers.
My solution in this case was to drop Avast and replace it with BitDefender, paid version on my main PC and the new free version (which as real-time protection) for the others.
Has anyone else had this issue, would be interested to know how you guys fixed it if you did?

I'm using online armor for the first time and it seems to be a good program.
However, I installed the KM Player and tried to uninstall KM because it stole a bunch of my file associations, but it wouldn't uninstall until I exited online armor altogether. Seems they don't play well.

Why not just remove the file association changes made at install via the KMP settings? For future reference, installing the free version of WinPatrol will enable you to block such changes in the event they are not wanted. Any firewall with a HIPS component is likely to interfere with some system processes because part of its function is to protect these. It just depends on the product (and how you have it configured) and is not a fault within the software of either product. MC - Site Manager.

I'm a little confused as to which is the best HIPS firewall. According to the quick selection guide, Private Firewall is the new number one yet, in the detailed review of each HIPS firewall, in the 'Firewalls With Strong HIPS Protection' section, it says "Comodo Firewall is the best choice for users seeking a full featured security suite".

Is it simply that the quick selection guide has been updated but the detailed reviews haven't, because those for Comodo and PrivateFirewall look just the same as when Comodo was still number one? Thanks.

The detailed review for Comodo was written back when it was the #1 choice, however others have since caught up and so, combined with other issues with Comodo, it's no longer the clear-cut #1 choice (at least for now). The biggest issue with PrivateFirewall, in my opinion, is the user interface is still not too user friendly, so the more beginner users may feel confused and overwhelmed with it. Comodo has a more simplier, user-friendly interface which they may prefer. Of course the advanced users probably won't have any problems with it. Hence why to date there is no "Gizmo's Award" for a top class freeware pick from the list. Of course that may change in the future, but right now seems more of a tie, and I felt it would be unfair to set the award when there is no clear-cut winner. Thanks for pointing that out though - I should re-word those sections to make it more clear. And I stuff rocks!

Wonderful reviews and information. Terrific site. One thing that seems
missing although I might be missing the obvious and that is do any of these
free firewalls provide any level of any kind of support.

I'm one week from expiration of Comodo commercial so a prompt response would be much appreciated. I found support from Comodo somewhat erratic.



I believe most of the free ones usually offer support mostly in a community forum. Comodo, for example, has one - but I can't say how good (or not) they are, whether for the commercial or freeware version. Some products offer so-called 'premium support' for their paid versions, where one can get responses from the team themselves, instead of from community forum members. Others do have a contact form where users could contact the developers directly, but other than PrivateFirewall (more on that below), I don't experience to comment in that regard. Perhaps someone else could chime in here. Greg Salvato, CEO of Privacyware, is quick to respond to queries in regards to PrivateFirewall, and is helpful with any issues that arise from the software. So in terms of support, they are probably at the top of the group.

Just an FYI about my experience with PrivateFirewall. I run XP Pro SP3 and installed this app b/c I needed to block an app that I bought from checking for updates. I used it for about a week and it hosed the IP stack. I was able to to fix the stack by using an uninstaller that I use to uninstall PrivateFirewall, and then did a system restore to the point before I installed it. Needless to say, I will not soon use another firewall app. Because like an idiot, I installed it on my production PC. I should have ran it in a sandbox but forgot about it. But I also did want to say that the write-up on this app was stellar, and spot on!! Sometimes of course, this sort of thing will happen. But I do know that the IP stack was healthy before I installed the firewall. Thanks for the great site Gizmo!!

I contacted Greg Salvato the CEO of Privacyware who is always quick to respond to support queries from Gizmo's Freeware members. In this case though he is confused, as I am, by the term "hosed the IP stack" used? Also, no details were provided of what happened for you to reach this conclusion? As it stands, he is 99% certain this issue is unrelated to Privatefirewall but will happily pursue it if more details are provided. MC - Site Manager.

I sometimes get to debug crashes that turn out to be triggered by incomplete uninstalls of older security software clashing with the networking subsystem and the current security software (Norton, McAfee and ZA are the most frequent culprits), so it's worth checking that you have fully uninstalled all old security programs by using the appropriate removal tool(s). I use the list here: but I'm sure there's a link to other lists here at Gizmo's too.

Great site satrow. I've not gone there until today. Very useful information. Thanks a lot.

does anyone know if outpost security suite free is still active?

i looked at the user reviews from and softpedia and the comments are from 2011 and 2012.


A firewall is a complicated topic. There are so many variables in correctly configuring a firewall to work properly. The star ratings given to these firewalls in this review are pretty much right on the money.
Novice users, I highly recommend using Zone Alarm. You have to go a long way to get out of the novice range, without some training, or heavy study.
More advanced users, I say Private Firewall is an excellent choice. Private Firewall is my choice of Firewall, to use on my computer.
Now if you are proficient at using and configuring firewalls. Comodo Firewall is in a class all by it self. But has to be recognized as one of the best software Firewalls on the market today, when configured properly. But it has a very steep learning curve, unless you are a Pro. Good Luck!

MC, you are quite right about the dangers of RegSeeker 1.55. One has to be very careful. For example, if Opera Browser has been uninstalled, and you search for Opera left-overs, you will get pages of keys. But, if you look carefully, you will see many blue "opera" keys, but followed by "tion" - so the search has produced many keys containing "operation."

But you don't have this problem with most well-defined program names e.g. "Comodo" or "Dragon" I find the free Revo Uninstaller leaves a lot of left-overs behind, both in Windows and the Registry. So I use "Everything" to search for left-overs in the OS - "Everything" does not search the Registry.

I have used RegSeeker for years, without a problem, using ONLY the Automatic cleaner, and never have I trashed my registry.

But as you rightly say, caution is definitely required.

Thanks for the comment.

How about testing's free tweakers? The "repair all-in-one" is quite something.,,

It's probably a little unfair just to single out RegSeeker because any program of this type is capable of the same as I inferred in my original post. We do however feel a need to keep posting a warning as this software type is responsible for more unbootable machines than any other cause. The situation is not helped by the amount of posts on the web saying something like "XXX reg cleaner hosed my system so now I'm using YYY and it's much better". What users fail to appreciate is, it is not the software at fault but themselves so the original mistake is odds on to be repeated no matter which program they choose to use. Security programs are the most difficult to remove without leaving traces behind because they often "hide" pieces of themselves around your system and by their nature are very entwined into it. That said, most vendors provide a removal tool and/or specific instructions for removal. Software that doesn't uninstall cleanly by these methods I would avoid from the respective vendor in the future. Only by voting with their feet can users influence developers to provide software that will not interfere with other products after the program has been uninstalled. My own recommendation is to image your system from a clean install of Windows but before adding any security software. This enables you to replace most of what you had cleanly and quickly should difficulties arise after a failed removal, and then add your new firewall/AV combinations later. It's also worth pointing out that most vendor forums offer advice about the specific removal of third party items that may be interfering with the installation and/or performance of their own product. This is by far the better route than relying on a registry cleaner scan that by it's nature will include sometimes many ambiguous entries. MC - Site Manager.

Hi to the best website in the world! A comment on Comodo Free Firewall, which is not as it used to be. I used it for years without problems, on your recommendation. However, the latest newest version caused me nothing but trouble, would not respond to my "Allow" clicks, and had so many popups that I eventually had to uninstall it. Then I could not get rid of the left-over registry entries.

A visit to the Comodo website enabled me to download and install "Comodo Registry Cleaner" and use it "at my own risk", as it is not a Comodo product, but provided by a Comodo user, to whom I say great work! It worked marvelously and cleaned all the uninstall left-overs from the uninstall (using Revo Free). As always I did a search using RegSeeker v1.55 after the uninstall, and found over a page-full of Comodo regisry keys which would not uninstall. It was then I used the third-party Comodo Registry Cleaner which did a thorough job.

Although it did not uninstall the Comodo left-overs, it readied them for uninstall, and RegSeeker uninstalled them first shot.

Comodo Free Firewall has deteriorated: after the uninstallation, my Internet Connection was gone. It took me a whole day to fix it, and this by using, as a last resort, " (Windows Repair all-in- one): a fantastic free program available from Major Geeks. On reboot, my Internet Connection was back.

Whilst on the Comodo web site, I read numerous complaints from folks who had had the same problem of having their Internet Connection broken by the latest Comodo Free Firewall.

I have now installed ZoneAlarm Free Firewall on my Windows 7 Pro and will also install a HIPS protector as you suggest. Best greetings and gratitude to TSAlert.

Also would like to add on that, I too had the problem of Comodo not properly uninstalling; any product that causes such problems upon removal doesn't really sit well in my books. Glad that you were able to eventually uninstall it successfully, and have found another great alternative!
Many thanks for sharing your experience. Just an advisory to users who may be curious but I have seen more Windows systems trashed by the use of RegSeeker than any other single piece of software. This is definitely a tool for the experienced, as indeed are all programs capable of deleting registry keys. It is so easy to delete shared entries or keys relied upon by other services to operate and the result can render your machine unbootable. MC - Site Manager.

Could this topic be updated again in some time? Online Armor has been at version since since October 2012 and I would like to see if it got better. Also the other firewalls should also have improved. I would also like to see binisoft windows firewall control tested. Sphynx also updated there version to version 5.x.

As soon as I get the chance I'll definitely be checking them out again and improving as needed - thank you for the comment

I've been using PrivateFirewall for a while now and i'm back here to see if i can't get something better.

I've gotten a lot of pop-ups, but that in itself is not a problem since i did put all the security settings to high.

The problem i'm having is that the pop-ups stay on screen and on-top of every other windows, for what seems an eternity, after i've clicked allow, now that is very annoying.

Also, this is a firewall and yet in all those pop-ups, i have yet to see the mention of a protocol, a url, an IP, a port or anything related to networking. Does that mean any program that i "allow" to run gets full network and internet access?

btw, i'm on Win XP if that makes a difference.

The kind of information you require can be found by clicking 'details' which is next to the 'options' button on the pop up.

See pages 12 & 16 in the PF guide, links in MC's post.

mmm ... now that's weird. I just opened Skype (that always gets me 2 pop-ups or more) and nowhere on the pop-ups can i see either "options" or "details". The only buttons are "Allow", "Train", "Terminate" and "Block".

I even removed Skype from the rules and yet all the pop-ups (much more numerous) i got had only the same 4 buttons.

I get four choices on both the firewall alerts and the process monitor alerts, 3 buttons (Allow, Block, Options) and a 'Details' link. I've only just started using it myself so I'm not sure I can help further, I just thought I would post about pages 12 & 16 (see also p23) as I had just been reading them in the manual. The manual is 62 pages long so you might find a reason in there why its not working for you.

I'm using PF on Windows 8 pro 64-bit so this is a difference but PF should support XP as well.

It's also worth noting that with most firewalls of this type, the nature, number and options possible from alerts will vary depending on how the initial configuration has been setup. Again, it is necessary to read the documentation thoroughly first and then decide which are the best options for your own requirements. MC - Site Manager.