Best PC Firewalls

Best software firewalls for Windows users

Online Armor Personal Firewall (*Est. $40 per year), by Tall Emu, is garnering kudos from testers and reviewers. It is the top-rated firewall in Matousec.com's latest battery of 84 leak tests, stopping 99 percent of attacks. Scot Finnie, editor-in-chief of ComputerWorld.com and owner of Scot's Newsletter Blog, tests firewalls for months to determine the best lightweight firewall (meaning that it interferes minimally with computing performance). He selects Online Armor, calling it "the best firewall I've ever tested, offering a blend of usability and hard-wired security that's near-ideal for maximizing protection and ensuring a good user experience." One of the key deciding points for Finnie is Online Armor's ease of use. He comments that finding the balance between security and user-friendliness is the biggest challenge for firewall developers. Online Armor, he says, "offers he best blend of a high degree of protection with a high level of usability."

Online Armor Free is a free version of Online Armor Personal Firewall, but it trails it in some important ways. One is protection. Finnie notes that "the paid version offers several additional security layers that are easily worth the $39.95 price of admission." Those security layers include web and mail shields, a phishing filter, keylogger detection, and domain name systems (DNS) spoofing protection. In the last batch of tests at Matousec.com, Online Armor Free is found to be less effective than the paid version, stopping just 86 percent of attacks, though that's still far better than average and impressive enough to earn a very good rating and recommended status.

According to Finnie, a more onerous issue is that while the paid version supports automatic updating, all updates in the free version must be done manually. That means uninstalling the previous edition, installing the new one, and restoring all of your security settings and preferences.

Because of those shortfalls, consumers looking for a free firewall might be better served by Comodo Internet Security, a free program that also includes antivirus and anti-spyware features. However that recommendation comes with some caveats.

Let's deal with the good first: the firewall in Comodo Internet Security is Comodo's Firewall Pro. Though no longer available separately, that firewall was a champ in both testing at Matousec.com and in reviews -- it is a former Editors' Choice selection at PCMag.com, for example. The firewall retains its protective prowess in its latest incarnation, stopping 96 percent of attacks in Matousec.com's latest battery of tests. That puts Comodo Internet Security right behind the paid version of Online Armor Personal Firewall and earns it a protection rating of excellent and recommended status.

Neil Rubenking at PCMag.com is also mostly impressed with the firewall in Comodo Internet Security, calling it "top notch." He runs his own leak tests instead of relying on the ones done by Matousec.com and finds a couple of vulnerabilities. He says that puts Comodo Internet Security behind some paid firewalls (though the specific ones he names test unimpressively at Matousec.com), but adds that it is notably better than any other free option.

Although Comodo's firewall is now only available in its Internet Security package, you can choose to install it and ignore the rest of the components. That's a very good thing because the rest of Comodo Internet Security is drawing some catcalls from reviewers. Despite liking the firewall, Rubenking awards Comodo Internet Security an unimpressive 2.5 out of five stars. He says the anti-spyware and antivirus features are ineffective in cleaning up and preventing malware infestations, while the system-monitor component, called Defense+, is overly obtrusive and prone to burying users under tons of excessive alerts and warnings.

Users posting at Download.com and FileForum.com give Comodo Internet Security good grades, though most comments seem to center around the firewall. Reviewers and editors at Softpedia.com also gave Comodo Internet Security a thumbs-up, but the site has since removed the program from its download list because of a dispute over the nature of an optional SafeSurf toolbar. See Useful Links for more information.

Comodo also offers an upgraded version of the software, called Internet Security Pro (*Est. $40 per year). While the basic Internet Security program is identical -- with its pluses and minuses -- the Pro version adds TrustConnect, a feature that's said to provide protection at Wi-Fi hot spots, and 24/7 live tech support that lets the company's technician's log onto your PC remotely and set up the software or diagnose and fix issues.

Agnitum's Outpost firewall is available in free and paid versions or as part of a security suite. Outpost Firewall Free 2009 finished right behind Comodo Internet Security at Matousec.com, where it is judged to be effective and recommended, however no opinions about usability are rendered. User reviews at download sites like Download.com and Softpedia.com are good thus far, but there's too little feedback to date to give them much weight.

Web User gives Outpost Firewall Pro (*Est. $40 for a one-year license, $60 for a lifetime license) it's highest rating and a Gold Award. However, much of that is based on the previous generation of testing at Matousec.com; since then, it's been surpassed in effectiveness -- albeit not by a wide margin -- by Online Armor Personal Firewall. Web User does say usability is good, and that Outpost Firewall Pro 2009 generally runs quietly and effectively, interrupting operations only for the most critical user decisions. The difference between the paid and free versions is that Firewall Pro adds some extra features such as spyware protection. However, the most glaring difference is that the free version does not provide for automatic updates.

Somewhat surprisingly, Outpost Security Suite Pro 2009 (*Est. $50 per year), which includes Firewall Pro, finished just behind the free version at Matousec.com. However, test results couldn't be closer -- just 1 percent separate the two -- and the firewall is still considered to provide excellent protection and is recommended.

Scott May, writing in the Columbia (Mo.) Daily Tribune, says that while he's tried dozens of different products over the years, he's "sold" on Outpost Security Suite 2009 and likes its "seamless and powerful" protection. An extended user review by Donna Buenaventura at BrightHub.com calls Outpost Security Suite 2009 an excellent package, and she notes that it's received complete certification from Virus Bulletin -- a very respected antivirus testing agency -- for its antivirus component.

Reviews of earlier versions say that Outpost Security Suite isn't the most user-friendly suite available. But a review of the current version at British website Pocket-lint says things are a bit improved thanks to the inclusion of a basic view that keeps things simple for the less technically inclined. However, as reviewer Paul Lester notes, the expert view opens users up to a tremendous amount of flexibility, but also to a much more confusing interface, making it hard to perform some common tasks such as controlling individual program access.

According to reviews, Norton Internet Security 2009 (*Est. $45) is the top-rated security suite overall. However, we've seen mixed reports about the effectiveness of its firewall. It unimpressively finishes in the middle of the pack at Matousec.com, with an effectiveness of just 66 percent and a rating of "good." It fails to earn a recommendation at that site. PCMag.com, however, conducts its own firewall testing and paints a somewhat cheerier picture. Neil Rubenking calls Norton's firewall tough and effective. For more information about Norton Internet Security 2009 and other security suites, see the separate Consumer search report on Internet Security Software.