Comodo Internet Security review

Comodo Internet Security is the best answer here to the question of which free firewall and antivirus to use together. Comodo describes it as antivirus combined with an enterprise-class packet filtering firewall, host intrusion prevention and automatic sandboxing of unknown files, and it says the free download is the full, completely functional version rather than a stripped-down one. The firewall lets you decide which programs may access the internet and blocks inbound and outbound attacks, and Secure Shopping runs the browser in an isolated container for banking. The trade-offs are real. It runs only on Windows, the page still lists Windows 10, 8 and 7, and the firewall and sandbox raise more alerts than a mainstream suite, which can confuse less technical users. The page also mixes free and paid offers, so read carefully before you click a buy button. If you want free protection without tuning, Windows Security with its built-in firewall is simpler.

Who it is for

Windows users who want a free firewall and antivirus together and are comfortable with technical alerts.

Price

Free full version for Windows; paid upgrades listed on Comodo's site.

Unlike the stripped-down versions of commercial software that other software vendors offer for free, this is the full, completely functional version of the product.
Quoted from the vendor pricing page on November 10, 2026.

Key features

• Enterprise-class packet filtering firewall that controls which programs reach the internet
• Host intrusion prevention
• Automatic sandboxing of unknown files with Valkyrie behavior analysis
• Secure Shopping, which isolates the browser in a container
• Antivirus and anti-spyware

Strengths and weaknesses

• Strength: Free, and Comodo says it is the full product rather than a cut-down version
• Strength: Firewall controls inbound and outbound traffic per program
• Strength: Sandboxing contains unknown files before they run freely
• Weakness: Windows only, and the page lists Windows 10, 8 and 7
• Weakness: Firewall and sandbox alerts can be confusing for beginners
• Weakness: The product page looks dated and mixes free and paid offers

Key facts

• Price: Free
• Platforms: Windows 10, 8, 7 listed
• Firewall: Packet filtering, inbound and outbound
• Extras: HIPS, auto sandbox, Secure Shopping

Where it ranks

Comodo Internet Security is No. 10 in our Best Internet Security Suites verdict.