The Best Free Antivirus in 2026

Most Windows PCs already have a free antivirus, so the real question is what a third-party free tier adds. Often the answer is cross-platform cover and a few extra shields, paid for with upgrade prompts.

Sometimes the answer is nothing, and the built-in tool is the better pick.

How we ranked: protection evidence first, then how much the free app pushes you toward paying, then which platforms it covers.

Three free products appear by name in AV-TEST's August 2026 table, and the rest are judged on their vendor pages with the lab result for the paid sibling shown separately.

Cyberpresso data: Toolradar's October 2026 security ranking evaluated 851 security tools, and only 5 of its 10 top picks have a free plan.

Of the 8 antivirus options below, 6 include real-time protection on the free tier, and the paid upgrades we could read cost 59%, 71% and 67% more at list price than the first-year deal. Prices are in US dollars from the vendor pages.

Kaspersky is not ranked.

The US Commerce Department's Bureau of Industry and Security prohibited Kaspersky Lab, Inc. from providing antivirus software and updates to US customers from 29 September 2024.

A free antivirus is the no-cost tier of a security vendor's product, or a tool that ships with the operating system.

It scans files for known malware and, on most tiers, watches the PC in the background so a bad download is blocked when it opens.

What the free tier drops is the point of the paid one: usually the firewall, anti-tracking, ransomware recovery, a full VPN and multi-device cover.

Free tiers are also the vendor's main advert, so expect banners that point to the paid plan.

Free antivirus does nothing about a stolen password or a phishing page you willingly type into.

Pair it with a password manager and an authenticator app, and read our guide to preventing phishing attacks.

The built-in option is better than its reputation. Microsoft says Defender Antivirus comes with Windows 11 at no extra cost, and AV-TEST's August 2026 report records it blocking every one of 297 zero-day samples in July and in August.

Its one soft spot is performance at 5.5 out of 6, so a slow PC may feel it more than it feels Avast or AVG.

Third-party free tiers earn their place on other axes. Avast, AVG and Avira run on Windows, Mac, Android and iOS for free, which Defender cannot do.

Bitdefender and Panda keep the product small, with Bitdefender stating that it alerts you only when it needs to.

The cost shows up later. Avast and AVG both quote a low first-year price for the paid tier and a much higher renewal, so a deal that looks like $47 turns into $80 at the second invoice.

Decide before you click through whether you will pay the renewal or drop back to free.

Prices below were read on vendor pages on 9 October 2026, in US dollars. Avast Premium Security for one Windows PC is $49.08 for the first year and renews at $77.99, while the 10-device plan is $69.48 then $99.99.

On AVG's store, Internet Security for one PC is $46.68 in year one and $79.99 at renewal.

Malwarebytes lists Standard for 3 devices at $59.99 a year, shown at $35.99 during its October promotion.

Defender, ClamAV and the free tiers of Bitdefender, Avira and Panda cost $0.

Their paid upgrade prices are not shown in text on the pages we read, so check the vendor before comparing.

Lab results come from AV-TEST's Windows home-user table for July and August 2026, plus the AV-Comparatives real-world factsheet for the same period. Defender, Avast Free and AVG Free appear there as free products.