Best Free Firewall Protection

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

Firewall products can be one of more cumbersome software products to use and have 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 the user at a near-perfect level, while not being too intrusive or complicated to handle. 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 on your experiences with the software products mentioned and/or freeware firewall products that you like, we would like to hear from you. Please refer to the comments section at the bottom of this page.

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Review Index


Basic Firewalls

The built-in Windows firewall is a common and popular choice since it passes all inbound tests (both stealth and open port), doesn't have many popup alerts, and doesn't cause system performance issues. It also does not require a separate software installation, since it comes built-in with modern versions of Windows. The built-in Windows firewall has improved drastically from earlier versions of Windows; the latest iteration, Windows 10, now contains a very capable and reliable built-in firewall solution, which is named Windows Defender Firewall.

You can also replace the Windows firewall with a basic third-party firewall which can provide 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. With the improved functionality of the built-in firewall in Windows 10, such third party firewall solutions are decreasing in popularity.

Windows Defender Firewall  

A firewall built into Windows with no separate installation required.

Our Rating: 
License: Commercial
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. Current iteration in Windows 10 is suitable for most daily users,
Primarily incoming connecting protection only. Advanced user interface is not user friendly - this interface may not be suitable for beginner users. Would be beneficial paired with a third party tool such as Windows 10 Firewall Control. May not provide adequate protection for "high risk" users.
Read full review...


A lightweight firewall solution that works with the built-in Windows Firewall.

Our Rating: 
License: Free
Lightweight basic firewall; simple yet effective. Non-intrusive program with no pop-ups. Ability to recognize associated processes when white-listing programs. This program could be a good choice for those not familiar 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.
Read full review...

Windows 10 Firewall Control  

A good choice to supplement the Windows built-in Firewall and compatible with Windows XP and higher.

Our Rating: 
License: Free (Limited features)
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.
Read full review...

ZoneAlarm Free Firewall  

A well-established inbound and outbound OS firewall solution suited for users of every level of experience.

Our Rating: 
License: Free (Limited features)
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.
Read full review...

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". We would only recommend these firewalls for these users; for average daily users, basic firewalls are likely sufficient.

Comodo Firewall  

A good choice for lightly-skilled and advanced users seeking a full featured security suite.

Our Rating: 
License: Free
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; remnants of the program are sometimes left on the computer.
Read full review...


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 more complex. There are more settings to configure than 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, especially the built in Windows Defender 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.


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.


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 and are unable to upgrade, we recommend using an active, supported program from the list above. 

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Related to Firewalls

Security Guides

Security Products

Inbound Vulnerability Tests

Outbound Vulnerability Tests

Learn More



This software category is maintained by volunteer editor Tim. Registered site visitors can contact Tim by clicking here.

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Please rate this article: 

Your rating: None
Average: 4.3 (546 votes)



I,m sure your view is held by all the software company's, that package these extra pieces of software in with their download. If it makes them feel better blaming the consumer, then more power to'em.

Hi there! After hearing much fanfare about Tinywall here and there I decided to create a 7x64 ISO with RT7Lite with firewall service turned on and give it a shot, being a bit of firewall compulsive as of late and after years of Comodo I just wanted to test it out... not a bad effort if you ask me, learning mode is a nice feature, but still needs a bit of polishing in terms of Gui and some weird behaviour, I noticed has a tendency of losing user settings and whitelists, reverting to default, this happened a couple of times, though it might just be hardware-depending, and does not have a confirm-upon-exit button, but that's not a major issue... the major drawback for me is that despite what's been said it's a bit of a resource hog, loads 2 processes floating around 25 MB each often peaking at 65+ which is nothing to fret about on 8Gb machines but could be a pain in the arse on older hardware, especially for something that's supposed to be feather-light... Comodo and Online Armor for instance both open up 4 processes, summing up roughly 50Mb during heavy usage. I ended up rolling back to Online Armor, which feels good for my needs, but if I had to pick up the main selling points of Tinywall they'd be its small and clean installer, learning mode, lack of conflicts with other software whatsoever, ease of use and no congestion on net performance

As with virtually all software agreed it certainly has its pros & cons. Depending on the user it just might be fitting for some, while others may require the more advanced-featured ones. Thanks for your comment!

I gave Private Firewall a test drive the other week, for a few days.

The GUI is ugly as anything but aside from that I liked it quite a lot. I found it quite easy to set up and use, the volume of pop ups is nothing too fazing if you're a long-term Comodo user and I found the whitelisting procedure somewhat quicker and smoother. The program as a whole seemed a lot lighter on resources than CIS.

The reason I went back to CIS was that I couldn't work out how to get PF working with proxies ... when I tried to use a PAC it seemed to confuse PF to the point of a system-hanging volume of log entries and the program I was trying to use not connecting.

Before that I tried TinyWall ... I really really like this one. It's so unobtrusive and simple that it's bordering on charming : )

I like the approach very much - refuse internet access to positively everything unless I say otherwise (it does have an included whitelist of Windows processes). I kept it for a week or so but on the whole I think it still needs some work - for instance whitelisting while it's pretty well implemented (the option to just click on an open window is great), doesn't allow multi-selection so if you whitelist by browsing files/running processes it can be a bit of a pain to do them all individually. For instance whitelisting all the execs that Avast needs to have net access means selecting one, closing the dialog, selecting the next, closing the dialog, etc etc. It can also be a time consuming process of trial and error working out exactly what processes a program does need access for in order to work. The promised ability to recognise child execs as belonging to a parent program didn't work for me either.

Drag and drop functionality would be a good addition, as would resizable dialogues.

Lastly it crashed on me several times while I was trying it out, which while it doesn't leave you "unfirewalled" (as TW is just a front-end GUI and hardener for the native Windows FW) is still not a great selling point.

I'll definitely be keeping my eye on any future development though. Meanwhile, back to CIS : )

Thanks for the write-ups Tim.

Some people seem to have had a few problems uninstalling Privatefirewall - how about you? Also, do you know if there's a removal tool that works with Vista?

As long time number one Comodo has been beaten by Privatefirewall for the top spot, would it be possible to do an installation and setup guide for Privatefirewall along similar lines to Chiron's excellent guide for Comodo Firewall?

That is a good idea, will look into it. Thanks for the suggestion!

Nice Article
but can we use any firewall for small business.
like one server is installed with firewall only and then provide internet surfing from that server to other system.
is there any free firewall there for 20-30 system.
please reply.

I just tried installing zone alarm free with their
zafwSetupWeb_120_104_000, but it requires
you to use ZONE ALARM SEARCH as your home page's search site and as your home page and new tab for all browsers, and as your default search provider for all browsers.

That's just freakin' nuts!

I would like to see version 7 of Online Armor tested. I understand, that you do not consider [edited out]. I just installed it (I bought it 2 years ago) and it seems that the Learning mode got removed completely. Though TinyWall is not bug free. From the beginning (2.0, maybe also 1.2, if I remember correctly) it loses it settings from time to time. That should be mentioned as well. Even though it is still the best GUI for the Windows Firewall.


I have noticed that Online Armour
looks like they NO longer offer their firewall as freeware!

They have updated their page.
That says it no longer free..

Always enjoy this site - Keep up the good work


Please read all the information on the Emsisoft website. "Isn't Emsisoft Online Armor Freeware? Yes and no. By default Emsisoft Online Armor installs as a free fully functional 30 day trial version. After the trial period you can either choose to buy a full version license or switch to the limited freeware mode. Of course you can decide to upgrade again at any time by simply renewing your license". Maybe less confusing are the external sources. MC - Site Manager.

Just FYI, I clicked the ZoneAlarm download link and went to major geeks, then click that link and ended up getting redirected to a link for anti-virus+firewall. Not interested in their anti-virus so I went to the ZoneAlarm site and downloaded it through them.

As Windows Firewall Notifier been tested?

I found it trough How to geek here:

It seems to do the same thing as Windows 7 Firewall Control, but it's even smaller and maybe the pop-ups and manuals are better, i don't know.

It's nearly portable.

Thanks for letting us know of the program - I'll certainly take a look at it. Although, on first review not sure how detailed any help manuals would be, being that it appears to be a native french site (as stated on the home page). It has also not been updated for over a year.

Hi, I followed the links in Paxmilitaris's post and found that Windows Firewall Notifier has gone open source and is now being hosted on CodePlex -

It's not easy to tell though if it's still being developed and updated ... on WoKhan's site the download is v1.8.0 (which links straight to CodePlex)and the date given is 28/4/12. However at the bottom of the old page, v1.7.0 has the same release date while the date on CodePlex for v1.8.0 is 11/11/13.

One to watch perhaps and see if it goes anywhere as an open source project. I'll probably give it a whirl sometime as I'm looking to start using W7 native firewall again.

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.