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 software 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 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 functionality 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.

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Review Index


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.

Windows Built in 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. 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 Windows 10 Firewall Control. Windows XP's version is very basic and lacks any outgoing protection. 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".


A proactive multi-layer security solution with behaviour blocking and standard firewall protection.

Our Rating: 
License: Free
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.
Read full review...

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 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.


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, we would suggest using another program that is currently active.

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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 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.

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