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.
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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". 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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Average: 4.3 (546 votes)


I have been obliged to uninstall COMODO Firewall recently because I had a problem with the last version of it.

I am using softwares like FreeFileSync or SyncFolders to backup my data with one way only mirroring on external HDs.

I don't want here to discuss if it is a good way of doing backups or not.

The problem is that after doing such a backup, if I immediately make the same backup, the same exact files that were copied in the previous backup will be backupped again, and the same thing happens each time I would immediately do the same thing again. It is as if the files were not backupped at all.

The backup software indicates clearly that everything went OK, that no problem occured at all.

I had not this problem with previous versions of COMODO Firewall which I use since a couple of years.

The backup software has the correct permissions from COMODO Firewall.

Does someone had the same problem or knows something about it ?

The problem related in my previous comment has been treated in the COMODO's Forum.

It is a problem concerning ADS (Alternate Data Stream) and timestamps.

The problem should be addressed by the month of April.

People having problems with version 8 of COMODO Firewall should revert to version 7 till the next version 8, which will maybe have brought a fix to this problem.

Something I've noticed with Online Armor is its high memory consumption compared with Comodo, around 60 mb to Comodo's 10mb or so, and judging by comments on the Emisoft forums I'm not alone. Otherwise it's a good firewall, easy to configure and understand. I'd still rather have Comodo though but v8 wouldn't install.

PS - My PC wouldn't boot after installing PrivateFirewall and I had to system restore from recovery options.

I've just abandoned today the long favorite Comodo Firewall, as I reformatted my system and now I can't install it for no reason, plus I always wanted to test something lighter, but I was kinda bored.

Anyone tested GlassWire? What's your opinion?

I'm reading from forums for large memory consumption, but the developers were trying to fix it.
Is it any good or should I give a try to PrivateFirewall, too? I've never used that either.

I'm without firewall at the moment.

Thanks and keep up the cool information. Love the users and their comments, too. My respect to you, too :]

Like you I've just abandoned my long time favorite Comodo. Version 7 worked fine but version 8 wont install despite following Chiron's guide on the Comodo forums to the letter - Comodo keeps on saying it can't load because Avast is incompatible despite me looking everywhere and, as far as I know, removing everything to do with Avast. I particularly liked the way you could bind applications with Comodo, for instance, to a VPN to safeguard against disconnects. I think you can do that with Windows 7 firewall too but of course it doesn't give the super protection Comodo does with D+ etc.

Hmm, I haven't thought of that. I have also the Avast antivirus installed.
So, the problem may be an incompatibility between these two applications huh?

It feels weird though, as before the format, the two of them used to cooperate normally.

I can't remember, if I had Comodo v7 installed at the very beginning and updating it afterwards or if I had installed v8 before Avast.

Anyway, I'm trying to get used to Private firewall, because I like the low system requirements that it has.

Yes, it could have been a Comodo/Avast problem. I was a long time Avast user and switched a few months ago to Comodo's full CIS suite when Avast stopped updating properly. I used both Avast removal tools but when I tried to install Comodo v8 was when I had all the problems. Over a week later and I've only now got an AV/firewall combo I'm happy with, Panda (great recent test results btw beating all other free AV's) and Online Armor.

Does Win 8.1 need a 3rd party firewall and a/v?

As I said I tried Windows 7 firewall control, then I took that off and tried Tinywall, which blocked my internet and I was not able to find out how to allow access.
So I've deleted them both and guess what? One of my browsers is unable to connect. I disabled windows firewall, still can't connect. So I set up a rule in Windows firewall allowing that program through. Still unable to connect.
I am at the limit of my technical know how so if I can't work out how to allow this program access I'll be forced to take 3 days to completely reinstall my machine.
I'd advise anyone with little knowledge to steer well clear of Windows 7 firewall control and Tinywall.

Windows 7 Firewall Control portable version needs some user account control permissions set before it can autorun at startup and work properly once started.
I don't pretend to even begin to understand the things you have to do to elevate it's permissions, and I've spent 2 hours trying.
So this is just a heads up, if like me you're not familiar with advanced techniques of permissions and user account control in Windows 7, give this programme a miss, it IS rocket science :)

All I want is something like this which allows me to allow/disallow anything from contacting/accessing through the internet, without having to go on some in depth learning curve about advanced windows scripting.
If anyone has any suggestions I'd be happy to listen.


Sphinx now call their firewall application "Windows 8 Firewall Control" (Windows 8/7/Vista/2008/2012/XP/2003).



Thanks MC for the update!

Hi MC ! Hope all is well! Just wondering if you have heard anything about/from PrivateFirewall as to when the next update or hopefully upgrade to a new GUI is coming? Been like 8 months now...

Hi darrin71 I doubt the GUI will receive a makeover but I sent a contact to the developers about their plans in general. Will post here as soon as I receive a reply. MC - Site Manager.
Greg Salvato the CEO of Privacyware was kind enough to respond in his usual timely manner. The product is still supported, but it is unknown when Privacyware will allocate the engineering resources necessary to develop the next update. This depends on various business orientated conditions that have yet to be realized. MC - Site Manager.

MC, any recent news or developments with Private Firewall? Also, assuming nothing new in the past year, does this lack of development lessen in any way the firewall's HIPS capability?

Unfortunately, there is nothing new I am able to add to the above. Unlike signature based systems, HIPS employ a range of methods to detect malware activity and in theory these should still hold good irrespective of the attack method. Malware writers however are always engineering new methods with the potential to bypass outdated prevention techniques. In this case, a product in active development such as Comodo would be a safer option. MC - Site Manager.

AVS firewall is no longer on the AVS website. Mostly audio/video software.

It is still there but now in a separate location for some reason. I have amended our product links accordingly. Thanks for drawing this to our attention. MC - Site Manager.
Is there any other firewall that gives you a widget like representation of traffic, like Comodo does? Is there any download link that let's you download just Comodo Firewall and not the full security suite?

Loved Comodo and been using it for a few years....but when I upgraded to 7.0 it just seemed to royally screw my system over. I wonder if there's guides or anything regarding this. I'm also getting tired of the ads they're starting to pop-up now every like 10 min.

Curious, I get no ads at all. I'm running the latest version of CIS.

Have you unticked "Show messages from Comodo message centre" in settings? I think that's the option related to ads and perhaps that got reset when the program updated to 7.

Is it screwing your system over in some other way, or just the ads?

If you've not seen it before, this is Chiron's useful guide to setting up the program -

I'm basically going through the same thing as this person posted here:

It basically made my computer unable to shut down (gets frozen on the shutting down screen), unable to install or uninstall programs (for some reason can't do windows update either), made certain programs unresponsive (may be the HIPS blocking it), and messed with my ethernet (because it installed something in my Local Area Connection properties). Everything returns to normal after removing Comodo while putting my computer in safe mode. After looking into it a bit, I think the security in 7.0 was just overly beefed causing me unable to do anything because it was just blocking everything, or the update reset my previous settings and just went back to being overprotective.....not entirely sure but it was not a pleasant experience. For now, I just removed Comodo and am trying out the Privatefirewall one until I can research why the 7.0 was screwing with my system.

This is just my opinion but even as the custodian of the HIPS review here, this type of software is always likely to "screw" up something, and certainly Comodo is not the only candidate. Even on a pristine system with no corruption that has never had a so called registry cleaner or "tweak" tool run on it, anything that either automatically or via user interaction controls every OS function is open to fail at some point. For general everyday use, I would always recommend a plain filtering firewall together with a classic AV and safe surfing practices as being the most efficient security combination. You might also find the AV-Comparatives firewall test PDF report linked from this Wilders thread of interest. MC - Site Manager.

Tried Tiny Wall again the other day to see how it's improved. It doesn't seem to have the ability to notify you of new connection attempts so you can block/allow. I guess it's designed for simplicity above all. Not my thing.

How TinyWall is designed to operate is explained on their site. Please note that comments about shareware programs or comparisons between them and free software are deleted as spam. MC - Site Manager.

Zonealarm installed itself on my computer, accompanied by Zonealarm search installing itself on each of my browsers as the default search engine.
I got rid of both, but it has reappeared.
This spyware is not detected by Spybot or Malawarebytes.

These extra items are only installed if you choose the option to do so during the install or upgrade process. There is plenty of advice on the web about how to avoid these (including installing the free version of WinPatrol) and/or how to remove them if you picked the wrong options. ZoneAlarm is just one of many software vendors who bundle extra components with the main program, but all are avoidable with proper care. See here for more information. MC - Site Manager.


Sorry to disagree with you. It is not true that extra items are only installed if you choose the option to do so. Most of the time they are automatic, unless you remove a check mark from a box. Some are automatic unless you choose custom install, so you can see the extra programs that are being installed. These software vendors are getting more and more sneaky about trying to get these extra items downloaded onto your computer. I got tricked just last week with a download of extra items.( I Look for these extra items very hard with every download. So you have to be very sneaky, to get one by me. And one did get by me last week) That is why I do all my downloads, sandboxed first. That is my suggestion to everyone now, is to sandbox all your downloads. That way you can see what you may have missed during the download.

Sneaky or not, the options are still there so whether you tick, don't tick or choose quick or default over custom this is still user choice and these extra items can only get on to your PC by making these choices. MC - Site Manager.