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Best Free Antivirus 2024: Top three options for staying safe online

It’s very important to have some sort of malware protection when browsing the web on your PC, so we’ve decided to round up the best free antivirus options of 2024.

Tests show that free antivirus solutions can be just as effective as paid-for alternatives. The only real differences are that paid-for options usually don’t have adverts, pack in more features and come bundled with extras such as VPNs and password managers. If that sounds like more your jam, then check out our Best Antivirus list instead

But if you only care about security and don’t fancy paying for a subscription, then you’re in the right place. Our experts have reviewed all of the most popular free antivirus options, and added the top scoring options to this very list. Keep scrolling down for our top recommended options.

How we test

Learn more about how we test antivirus software

For raw performance against malicious software, we use data from multiple testing houses: AV-Test, SE Labs and AV-Comparatives. Of these tests, we prioritise ‘real-world’ performance, in which antivirus detection engines are exposed to live threats. 

We also draw on system performance data captured by AV-Test and we inventory and compare features on an application-by-application basis, highlighting both useful tools and unexpected sticking points in the workflow and interfaces.

Avast One Essential

Best overall antivirus
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  • Works on Windows 7 & 8.1
  • Very accurate
  • Ransomware defence


  • More false positives than some rivals

Avast One Essential has ascended to the top of the list as the very best free antivirus of 2024, and that’s for one key reason: it prevented 100% of malware in the latest string of tests. It did see a few false positives, suggesting it may be a little too militant, but it’s still great to see a third-party antivirus post even more impressive performance results than Microsoft Defender Antivirus, which is built into Windows 11 by default.

That said, the performance difference isn’t big enough to make an upgrade essential if you’re using Windows 11. Avast One Essential becomes more useful if you’re using an outdated operating system.

Avast One Essential is partly funded by advertising and partner promotion. It has a number of useful features, carrying out real-time scanning of potential threats, as well as on-demand and scheduled system scans. It even has a built-in do not disturb mode that’s automatically activated whenever you run a fullscreen application.

You will get far more features from paid-for services such as McAfee Plus Advanced and Norton 360, but if you don’t want to spend a penny while still seeing top-grade security, then Avast One Essential is our top recommendation.

Reviewer: K.G. Orphanides
Full review: Avast Free Antivirus Review

Microsoft Defender Antivirus

Best overall free antivirus
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  • Excellent integrated Windows 10/11 interface
  • Excellent malware protection
  • No need to install anything
  • Free


  • System impact isn’t as low as you might expect

Built into Windows 10 and 11, Microsoft Defender is the one of the most consistently reliable antivirus suites around. It got perfect 100% protection scores in AV-Test’s most recent tests, 99.5% in AV Comparatives’ latest real-world test and 100% in SE Labs’ tests. That’s top-flight performance, although AV-Test did also find that Defender can have a greater impact on system performance than third-party antivirus solutions.

Core anti-malware components include real-time protection and on-demand scans covering everything from quickly checking a folder to a comprehensive offline scan that checks for hard-to-remove threats such as rootkits by scanning the system without booting into Windows. However, scheduled scans have to be set up via Windows Task Scheduler.

As well as virus protection, Defender includes Windows Firewall, parental controls and remote management of your family’s devices, reputation-based site blocking in Edge and application blocking in general, system health reports, and the ability to disable all notifications.

Overall, Microsoft Defender is so good that there’s no real need to go looking for third-party alternatives. But Avast One Essential did see a better performance in the latest tests, while paid-for options will always offer more features.

Reviewer: K.G. Orphanides
Full review: Microsoft Defender Antivirus Review

Avira Free Security

A mediocre antivirus with lots of features
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  • Works on Windows 7 & 8.1
  • Includes lots of extra tools
  • Effective malware defence


  • Ransomware defence isn’t included
  • No silent mode

Avira has a longstanding reputation as a lightweight antivirus suite that’ll run on almost anything. That makes it a good alternative to Microsoft Defender if you’re using a dated version of Windows.

Avira has been a little inconsistent in regards to performance results over the past few years, but it saw fantastic results in the latest round of testing, achieving 100% protection for AV-TEST and SE Labs, and 99.8% for AV Comparatives.

Free users only get access to the real-time protection module, plus scheduled and on-demand scans. If you want the dedicated web, email and ransomware protection modules, you’ll be prompted to subscribe to Avira Prime. Similarly, the free version has no do-not-disturb mode for gaming.

It comes with plenty of other tools for system optimisation, file shredding, and tweaking Windows’ privacy settings, plus a very limited 500MB/month VPN allowance. These are all handy, but can’t quite outshine Microsoft Defender for Windows 10 and 11 users.

Reviewer: K.G. Orphanides
Full review: Avira Free Security Review


Is free antivirus safe?

Yes, all of the antivirus options listed are safe to use.

What is the difference between free antivirus software and paid antivirus?

Both forms of antivirus can detect and block malware, but paid-for options can unlock additional features such as VPNs and advanced parental controls.

Which antivirus is free forever?

Every antivirus listed is free for an unlimited time. But you will need to pay for the premium tier if you want to unlock additional features.

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