Best antivirus for Windows PCs 2021: Reviews and guidance

Antivirus software is nearly as crucial as a PC’s operating system. Even if you’re well aware of potential threats and practice extreme caution, some threats just can’t be prevented without the extra help of an AV program—or a full antivirus suite. 

You could, for example, visit a website that unintentionally displays malicious ads. Or accidentally click on a phishing email (it happens!). Or get stung by a zero-day threat, where an undisclosed bug in Windows, your browser, or an installed program gives hackers entry to your system.

We’re not suggesting that PC security software is fool-proof. Antivirus software often can’t do much to stop zero-day exploits, for example. But it can detect when the undisclosed vulnerability is used to install other nasty bits, like ransomware, on your machine. Anyone who actively uses email, clicks on links, and downloads programs will benefit from an antivirus suite.

Our recommendations strike a balance between excellent protection, a worthwhile selection of features, and minimal impact on your PC’s performance. You can read about how we test antivirus suites below. 

Updated on 11/23/2021 to include our review of Avast One, which represents big strides for this stalwart antivirus maker. There is a lot to like here, including a good price, good performance, and useful extra features. See links to all of our antivirus reviews at the bottom of this article.

Best antivirus suite 2021

Norton Security Premium is no more, but our pick for best AV has stayed in the family, with Norton 360 Deluxe. There aren’t a lot of fundamental changes to the suite compared to previous iterations, which also means its just as solid. The pricing now covers fewer devices, but you get a good number of extra features such as Dark Web Monitoring and VPN access, making for an overall excellent value.  

Best budget antivirus suite

AVG Internet Security does an excellent job of protecting your PC, but it’s interface could be a lot better. Nevertheless, with unlimited installs for $70 per year, it’s hard to beat this popular security solution.

Best free antivirus suite

If Windows 10 is already working, why add anything else? If its built-in security suite, Windows Security, performs on par with the best of the free AV options—as we discovered in our roundup of the best free antivirus—why add the extra baggage of a third-party program? Sure other AV programs might offer marginally better protection, but not enough to outweigh the convenience of rolling with Microsoft’s home-grown offering. Windows Seucrity also has ransomware protection, which many free options don’t. Plus, you avoid the nuisance of a third-party suite’s regular upgrade notifications. To learn more, see our video on How to use Windows Security, or read our full review.)

Best antivirus suite for beginners

Many antivirus suites create an interface that’s as simple as possible for users to understand—but sometimes the software becomes too stripped down. That’s why our recommendation for novices is Trend Micro Maximum Security.

This antivirus suite, which provides highly rated protection, strikes a nice balance between complexity and simplicity: Four category icons at the top let you dive deeper into the suite, but if all you need to do is a scan, that option is right there in the center of interface. You can’t miss it. 

Overall, no matter what you need to get done in Maximum Security, the interface doesn’t leave you with any guesswork.

What to look for in an antivirus suite

There are three basic requirements that an antivirus suite needs:

• High detection rate for malware and other threats
• Low impact on system resources
• An easy-to-use interface

That’s not all to consider, however. These days, many security suites come with extras such as a backup service for your most essential files, Android apps for mobile security, a more advanced firewall, family protection (read: child restriction) features, and the right to use the program on multiple PCs. Whether you need those extras depends on your personal situation.

How we test

First, we take a look at the interface to determine how easy or complicated it is. Does the interface make it easy to get at essential tools like PC scans and password managers, for example, or is everything buried under multiple clicks? Are there elements that look like they should be clickable but aren’t? Are alerts interactive or purely informational, and does that make sense in context?

We also examine the features on offer. Every good antivirus suite should have the basics like scanning and real-time protection, but many vendors offer elements that go beyond basic security like password managers or firewalls. We try to discern whether any of these extra features are particularly useful, or just frills that look nice but don’t serve a practical purpose.

To test the suite’s demand on system resources, we run two benchmarks. The first is PCMark 8’s Work Conventional test, which simulates a variety of workloads including editing spreadsheets, browsing the web, and running video chat. 

We run the benchmark before the security suite is installed. Then we install the software, have it run a full scan on our Windows 10 test machine, and start a second run of the benchmark at the same time. Then we compare the overall scores to see if the decline between the two benchmarks is significant.

As a harsher stress test, we also use Handbrake to transcode a video before and after installing the A/V. On most home PCs, this encoding task utilizes 100 percent of the CPU. We then compare transcoding times to see if there’s any significant decline.

Our test machine is an Acer Aspire E15 with an Intel Core i3-7100U, 4GB RAM, and a 1TB hard drive. Each security suite is tested on a clean install of Windows 10 Home.

As for the antivirus suite’s detection capabilities, we’ll rely on the opinions of security researchers dedicated to this task. We’ll take into consideration reports from outlets such as A-V Comparatives, A-V Test and SE Labs. 

We’ll also take pricing into account and what you get for it. 

Whenever possible we’ll review security suites using a free trial to get a sense of what consumers see when they first try out a new product.

Best antivirus: All of our reviews

Looking for a cheaper option or something with more flexibility? Or perhaps you just want to see what else is out there? Below is a list of all the antivirus suites we’ve reviewed. We’ll keep evaluating new ones and adding them here, so be sure to come back to see what else we’ve tested.