10 Best Free Firewall Programs

Comodo Firewall

Comodo Firewall has useful features like virtual internet browsing, an ad blocker, custom DNS servers, a Game Mode, and a Virtual Kiosk in addition to options to easily block any process or program from leaving/entering the network.

I especially appreciate how easy it is to add programs to the block or allow list. Instead of walking through a long-winded wizard to define ports and other options, you can just browse for a program and be done. However, there are also very specific, advanced settings, if you want to use them.

Comodo Firewall has a Rating Scan option to scan all running processes to show how trustworthy they are. This is especially useful if you suspect that some kind of malware is running on your computer.

Comodo KillSwitch is an advanced portion of the program that lists all running processes and makes it a breeze to terminate or block anything you don't want. You can also see all your computer's running applications and services from this window.

It might take longer than you're used to for it to install. It's said to run on Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP.

TinyWall

I like the free TinyWall firewall program because it provides protection without displaying tons of notifications and prompts like most other firewall software.

An application scanner is included in the program to scan your computer for programs it can add to the safe list. You're also able to choose a process, file, or service manually and give it firewall permissions that are permanent or for a specified number of hours.

You can run TinyWall in an auto-learn mode to teach it which programs you want to give network access to so that you can open all of them, and then shut down the mode to quickly add all your trusted programs to the safe list.

A Connections monitor shows all the active processes that have a connection to the internet, as well as any open ports. You're able to right-click any of these connections to abruptly terminate the process or even send it to VirusTotal for an online virus scan.

Some other things I like are that TinyWall blocks known locations that harbor viruses and worms, protects changes made to Windows Firewall, can be password protected, and can lock down the hosts file from unwanted changes.

Unlike the programs further down this list, you can use TinyWall on a modern computer running Windows 11 or Windows 10. It also works with Windows 8, and Windows 7, as well as Windows Server 2019, 2016, and 2012 R2.

GlassWire

I like the GlassWire firewall program because of its incredibly simple user interface that organizes all of its functions very well.

There are five tabs that run along the top of the program:

• The first tab is Graph, which lets you see a real time view of apps using the network and the type of traffic they're using, as far back as one month. This is also where you go to see when any specific program first connected to the network.
• In the Firewall tab is a list of actively running programs, and you can see exactly which hosts each program has an established connection with. If you want to block that program, just click the icon to the left, and it'll instantly no longer have access to the web.
• Usage details how much data each app has used today, this week, or over the whole month, both incoming and outgoing traffic. View all apps together or select specific ones from the list to see usage ordered by host and traffic type, such as HTTPS, mDNS, or DHCP.
• The Network tab isn't supported in this version of GlassWire, but if you were to buy the program, you'd be able to see the devices detected on your network and receive alerts when new ones join.
• The Alerts section is a hub for all the alerts GlassWire collects, such as when a program was first identified as using the network and what host it connected to.

In GlassWire's menu is an option to go incognito, which will prevent the program from logging all traffic until you turn it back on. There's also a snooze option to disable all notifications for 24 hours. In the settings are additional features like to launch the program at startup and to turn on or off specific alerts, like for bandwidth overage, changes made to proxy settings and/or DNS servers, and ARP spoofing detection.

Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP are supported.

ZoneAlarm Free Firewall

ZoneAlarm Free Firewall is the basic version of ZoneAlarm Free Antivirus + Firewall but just without the antivirus portion. You can, however, add this portion to the installation at a later date if you wish to have a virus scanner alongside this firewall program.

During setup, you're given the option to install with one of two security types: AUTO-LEARN or MAX SECURITY. The former makes changes based on your behavior, while the latter gives you the ability to control each and every application setting manually.

ZoneAlarm Free Firewall can lock the hosts file to prevent malicious changes, enter into Game Mode to manage notifications automatically for less disturbance, password protect its settings to prevent unauthorized changes, and even email you security status reports.

You can also use this program to easily adjust the security mode of public and private networks with a slider setting. Slide the setting from no firewall protection to medium or high to adjust whether anyone on the network can connect to you, which allows restricting file and printer sharing for certain networks.

I tested this program in Windows 10, but it should work fine in other Windows versions, too.

PeerBlock

PeerBlock is different from most firewall programs because instead of blocking programs, it blocks whole lists of IP addresses under certain category types.

It works by loading a list of IP addresses that the program will use to block your access to—both outgoing and incoming connections. This means any of the listed addresses won't have access to your computer in the same way you won't have access to their network.

For example, you can load a list of pre-made locations to block IP addresses that have been labeled as P2P, business ISPs, educational, ads, or spyware. You can even block entire countries and organizations!

You can make your own list of addresses to block, or use several free ones from I-BlockList. Some lists are also available during installation. Lists you add to PeerBlock can be updated regularly and automatically without any intervention, which is perfect so you don't have to maintain them yourself.

It works in Windows 11, Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP.

Privatefirewall

There are three profiles in Privatefirewall, allowing for easy switching between unique settings and firewall rules.

The list of applications that are allowed or blocked is very easy to recognize and alter. You can add new applications to the list and clearly see which are blocked and which are allowed. It's not confusing in the slightest.

When editing the access rule for a process, there are really advanced settings like defining whether to allow, ask, or block the ability of the process to set hooks, open threads, copy screen content, monitor clipboard content, initiate a shutdown/logoff, debug processes, and many others.

When you right-click the icon for Privatefirewall in the notification area of the taskbar, you can quickly block or filter traffic without any prompts or extra buttons. This is a feature I appreciate in programs like this because it provides quick access to the app's main function, which, in this case, means it's a simple way to quickly stop all network activity at once.

You can also use Privatefirewall to restrict outbound email, block specific IP addresses, deny access to a network, and disable access to custom websites.

It's said to work on Windows 7, Windows Vista, Windows XP, and Windows 2000.

NetDefender

NetDefender is a pretty basic firewall program for Windows, as you can see from my screenshot. Still, it's a useful program if you're running an older version of Windows.

You're able to define a source and destination IP address and port number, as well as the protocol to block or allow any address. This means you can block FTP or any other port from being used on the network.

Blocking applications is a bit limited because the program must be currently running to add it to the block list. This works by simply listing all the running programs and having the option to add it to the list of blocked programs.

NetDefender also includes a port scanner so you can quickly see which ports are open on your machine to help realize which of them you may want to close.

It works officially only in Windows XP and Windows 2000, but it didn't cause any trouble for me in Windows 7 or Windows 8. It did, however, fail to start in Windows 11.

AVS Firewall

AVS Firewall has a very friendly interface and should be easy enough for anyone to use.

It protects your computer from malicious registry changes, pop-up windows, flash banners, and most advertisements. You can even customize the URLs that should be blocked for ads and banners if one isn't already listed.

Allowing and denying specific IP addresses, ports, and programs couldn't be easier. You can add these manually or browse through a list of running processes to choose one from there.

AVS Firewall includes what's called Parent Control, which is a section to only allow access to an explicit list of websites. You can password protect this section of AVS Firewall to prevent unauthorized changes.

A history of network connections is available through the Journal section, so you can easily browse through and see what connections have been established in the past.

This program works in Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP.

R-Firewall

R-Firewall has all the features you'd expect to find in a firewall program, but the interface isn't very easy to use. Also, I don't like that there aren't any inline instructions that help explain what a change in settings will do when applied.

There's a content blocker that terminates browsing by keyword, a mail filter to block cookies/javascript/pop-ups/ActiveX, an image blocker to remove advertisements that are a fixed size, and a general ad blocker to block ads by URL.

A wizard helps apply rules to several programs at once by detecting the software that's currently installed. R-Firewall was unable to find all the programs I had installed, which makes sense considering this program's age, but it did work correctly for those it could find.

It worked for me in Windows XP, but not in Windows 11. It's possible it'll work in other Windows operating systems, but I can't confirm that.