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 are arguably 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 to user at a near-perfect level, while not being too intrusive or complicated to handle. The type of user, including what the user usually uses their computer for, 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 on your experiences with the software products mentioned and/or freeware firewall products that you like, 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 that is much better 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 is likely 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.
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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.
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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.
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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.
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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.
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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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Average: 4.3 (542 votes)


Just thought I'd inform everyone that Privacyware site no longer exists. Bummer... This firewall is still available at Softpedia but is version NOT . If you install this firewall you will find out that the zero day protection and alot of other features no longer work because they are dependent on Privacywares server which no longer exists.

PrivateFirewall still outperforms most of the other Free options out there. Even without "Zero Day" features.
As for ver It is still freely available at a number of sites: Would recommend the TomsGuide site.,0301-33843.html

While I really like the firewall Comodo offers, I cannot use & will not recommend anyone else use, as you cannot fully disable the. anti-virus aspects of their software, even if you explicitly try to, or attempt to only install the firewall. i told it during installationthat I only wanted the firewall, but it gave me everything anyway, and while I had been running it before, even though I disabled the anti virus, it decided it would constantly block my attempts to run things and NEVER notify me about it, so I thought I was having computer problems. It took me forever to figure out Comodo was the damn culprit! Now it has earned itself a spot in my most loathed software, especially because of their greedy underhanded tactics to install crap you explicitly say you don't want, and then trying to ram their other products down your throat.

Hi, folks:

Guessed you might like to know about SimpleWall (1.6), an apparently promissing free firewall, with language support, available at .

Kind regards from Rio, Niterói, Brazil. ;)

Comodo all the way! It also acts as malware protection for me. With the sandbox enabled, it blocks all nasties I can throw at it. Even tested Ransim against it and it blocks all the simulated ransomware.

Though I must point out that I got the ideal settings from someone quite knowledgeable about all things CF. Not sure if I can point you guys to some of her review vids, but they are quite helpful. I used to use binisofts paid product, but noticed that I can do all that it does on CF using the "custom ruleset" in the firewall options. Then it will ask before letting anything make a connection out and you can filter requests as you wish.

I have been running the free version of GlassWire for several weeks now - not as a stand alone firewall but in conjunction with my inbuilt Windows 10 firewall. Whilst it is generally not advisable to run two firewalls together GlassWire is designed to run along side the Windows firewall and provides considerable additional useful information and operates unobtrusively after a brief training period where the user vets connection alerts related to installed programs and apps.
Don't know what level of protection it would offer on its own but as an adjunct to Windows firewall it is an excellent and very user friendly tool which is being continually improved and developed (latest update yesterday).
I was somewhat sceptical of GlassWire initially because of the rather gimmicky colorful graphics but I am glad I tried it and it is a definite keeper on my computers.

GlassWire is only a firewall in the sense that it is a front-end to Windows Firewall. If you disable Windows Firewall then the GlassWire firewall features will also be disabled. Quite a few users don't touch the firewall features - I am one that doesn't - but it might be useful one day if I get a malware infection and want to use the firewall feature to block all network access.

I mainly use it as a system monitor to keep track of all applications and devices interacting with the network from my computer. Many people use it only for bandwidth monitoring as a lot of people have quotas on their Internet connection. If they want to monitor all their network traffic then they put it on every computer.

P.S. I adopted it when I first heard about it here. I liked it so much I've paid for a full version even though I only need the free features.

anyone have checked "GlassWire" yet?

Also, check out Windows Firewall Control from Binisoft (different software from Windows "10" Firewall Control).

Just FYI, Jetico Personal Firewall is now freeware as of April 13, 2016 for those of you in need of an excellent firewall w/ HIPS for Windows 8 and older...


Please, try and consider adding in list, another free firewall called "Free Firewall". I haven't used it, but I read good reviews about it.
Can be found here:

PS: Windows Firewall seems to be essential now for Windows 10, as if you disable it, you cannot receive automatic Windows updates o.O

While looking for a new firewall, I chose to go back to Comodo, which I have used in the past with good results. Bad move. While I had no technical errors or problems installing in Windows 10, the first thing I saw it install was Geek Buddy! I saw no option made available in install to not install this program. I am usually pretty good at catching this. I did catch where it wanted to change homepages and search engine.
So off the uninstall Geek Buddy - Not happening. Uninstall button was disabled in add/remove programs. So I uninstalled Comodo and guess what - it left Geek Buddy behind on my computer. Thankfully this time the uninstall button was enabled so I could get rid of it. Then scanned for leftovers just in case.
I would not have expected this from Comodo, so I will no longer consider it as an option anymore.

Although it has been a long time since I installed Comodo, I was sure there is an option to choose what to install, which for me always did not include the annoying GeekBuddy.

I honestly was on with PrivateFirewall, until in messed up a handful of my computers. The computer would start and it would give me a black screen. I looked it up and tried to fix it, but I never found a solution. Had to format my PC for that. Keep in mind I do not say something like "OMG THEIR PROGRAM DESTROYED MY PC! DEFINITELY A VIRUS! DO NOT INSTALL!". I usually laugh at people that exaggerate like that. But it did it 5 times, 3 being on my main PC.

I returned to Comodo mostly cause I am used to it and I know where to go and what to adjust to make it work. Just to check it out I just downloaded the installer of Comodo Internet Security. Seems the option is still there when you install it.

When the installer starts, on the bottom left there is a customize option. You click that and you can enable and disable what you want. I used to disabled only GeekBuddy in the past, but now I disable Chromodo too, since I use Comodo Dragon instead. But the option is still there to disable what you want.

Hi tim,
thanks for this very intreresting paper!
And what about "Sophos UTM Essential Firewall", free for home users? Did you tested it? I'd be quite glad to have your opinion about it.
Best regards

"You will need a dedicated computer to use Sophos firewall application"... so it is therefore outside the scope of this review. MC - Site Manager.

You're right... I didn't notice that! Thanks for answering so fast!

BEWARE FOR COMODO on windows 10! It gave me huge problems and difficulties to uninstall. After boot I only had a black screen, and couldn't run anything. I couldn't even get in safemode and it even gave me my first BSOD in windows 10. Had to use Linux to straighten things up. NOT FOR BEGINNERS.

Windows 10 firewall control has a very, very, very annoying sound, so uninstalled it straight away. Please, developers, get rid of that sound!

Zone-alarm is getting too little credit here. It's really a "fire-and-forget" kind of software, with more than enough possibilities if you want them.

Software always will give problems. That does not make them bad. Definitely Comodo always had and probably still have issues with BSODs and you can see so in their main site too. Obviously a lot of them happen because of conflicts though, rather than just the product. Of course updates do not happen without reason too.

I had a black screen problem with Private Firewall and not only once, but I remember it happened always when I did something specific. But either way, I have been using Comodo Internet Security for many years now and I do not get problems from it. It runs along MalwareBytes Antimalware with no problems and it is fine.

But I agree. Definitely not for someone that wants to start it up and forget it.

It is very easy to blame software for system problems that can be caused by a variety of other issues. I know plenty of folks using Comodo with Windows 10 and having zero issues. MC - Site Manager.

It's just intended as a big warning, not a blame. I recently installed Windows 10, and there's only some other securitysoftware there, like malwarebytes and bitdefender. Other firewalls didn't give any problems.

The current Windows firewall is in fact better than most third party alternatives unless of course you install untrusted software in which case nothing will protect you. It also depends on how you configure Comodo to work with other software. This is highlighted in many places including Wilders. MC - Site Manager.

I think the 3 star rating for Comodo is about right. Excellent protection but a nightmare to uninstall. Even if you follow Chiron's lengthy clean install guide (and how many average users are prepared to do all that?) there is still a good chance you will have serious issues, as I found, eventually having to ditch Comodo after numerous BSOD's and failure of V8 to install properly. Until Comodo rectifies this I don't think it can be recommended. Sure, there are other security products that don't always uninstall cleanly, but none I've used have been anywhere near as problematic as Comodo.

Used PrivateFirewall for a long time (on my Win XP), but now with Win 10 I gave up on 3rd party options. One thing that annoys me with Windows built in firewall is user unfriendly interface when you want to block connection for some specific file. Found one simple program that allows you to do that. The whole program has about 600 KB. You can even add option to explorer contex menu to block specific files from there. Program doesn't install, it's portable. You can start it from anywhere, but then it does copy itself with ini file to Windows Program Files section.

Can't add link, so try googling "Firewall App Blocker" by Sordum.

just a disapointment:
when I click on the link "Security Wizard" in the introduction, I'm given a message: OUPS§ NOT FOUND
In spite of the fact that the article is recent
hat's happen? Could you help?

Hi Camile, thanks for your comment. The security wizard has been discontinued from our site at this time. I invite you to visit our forum for any questions or comments you may have on selecting the appropriate security software

I'm surprised after reading the pros/cons for Comodo that it didn't get more stars. Sure it installs the AV files, but I can live with that if everything else is 5 stars. As for potential uninstall leaving remnants...most software does that anyways.

I've been using Private Firewall for several months now with good success. I find the popups quite handy as (being paranoid) I want to know exactly what programs and software are attempting to access the internet. I'd also give it a 5-star.

Hi MC! Hope all is well. Well I have to ask you if you have heard anything from or if you can contact Privacyware regarding a Windows 10 compatibility update. As you know there is a lot of people out there who love Privatefirewall, me included...which brings up another question for you, how can you disable trusted publishers in Windows 7 firewall? Reason is Qihoo is trying to force people to upgrade from 360 Internet Security to Total Security. Total Security, as you know is not the same product, however Total Security Essentials is. If I want to wait to see how Total Security Essentials develops before I decide to upgrade then I should be able to block the 360 Total Security Online installer rule 360 just made in windows 7 firewall. Correct?? Why is it everytime 360 updates its virus definitions it changes the 360 Total Security Online installer rule it made from "my blocked setting" to allow? As usual I thank you for your time and consideration and any links you can provide.

Hi darrin71. Management of trusted publishers is detailed here.

The two things that annoy me most are popup windows for "are you sure you really want to exit" and apps that overwrite permission rules. Regarding 360, I guess you're stuck with this behaviour because no doubt the permissions granted for the program at install are what allows it to overwrite your block rule. Although not an ideal solution for you maybe, but I would suggest switching to Panda until the full direction of the 360 products becomes more clear. I have Panda on two machines and neither have been compromised by anything nasty and what money I do have is still in my bank account. :D

Regarding Privatefirewall, I've sent a contact to the vendor and will post their response here as soon as I get it. MC - Site Manager.