EDITOR'S NOTE: The winners of the 2021 Tom's Guide Awards have been announced, and Kaspersky Total Security has won Best Antivirus Software. Bitdefender Total Security is the runner-up. Head to the Tom's Guide Awards 2021 Best Products for Working From Home page to see all the winners and recommended runners-up.
If you've got a Windows PC, you're going to have to use one of the best antivirus programs, whether that program is free or paid. That's because Windows is by far the most widely attacked software platform, and letting your PC go without antivirus software is just inviting trouble.
Fortunately, Windows 10 and Windows 8.1 have built-in software called Microsoft Defender Antivirus (formerly Windows Defender), and it's one of the best free antivirus programs. But it doesn't completely match the protection and features offered by the best paid antivirus software.
Paid antivirus software adds dedicated defenses against ransomware and webcam hijacking, builds in extra functions like file shredding or encryption, and sometimes includes features that normally are available as stand-alone services, such as password managers, cloud-backup solutions, VPNs or identity-theft protection.
Paid antivirus programs normally come in tiers that share the same protection against malware, but add on more features and functions as the yearly subscription prices rise.
Kaspersky, for example, offers four different packages: the free Kaspersky Security Cloud, the basic paid entry Kaspersky Anti-Virus, the midrange Kaspersky Internet Security and the premium Kaspersky Total Security. Another top antivirus maker, Norton LifeLock, has eight plans mixing in various levels of protection against malware and identity theft.
These different tiers of service are aimed at different customers according to their needs and spending power, which we explore further at the end of this page. In the meantime, here's our list of the best paid antivirus software, but don't forget to check out our list of the best free antivirus software halfway down this page.
The top 3 best antivirus brands
1. Kaspersky provides the best antivirus protection overall
Kaspersky combines one of the world's top-rated malware-detection engines with a ton of useful features. It's the best antivirus software you can buy today.
2. Bitdefender offers the best value in antivirus software
Bitdefender Antivirus Plus combines great malware protection with an assortment of useful features and an easy-to-use interface, all at a great price.
3. Norton packs in everything but the kitchen sink
Norton's antivirus products offer a password manager, unlimited VPN data, identity theft protection, parental controls and even online storage -- almost every kind of digital security you could ever need.View Deal
What is the best antivirus software?
Our first choice for best antivirus software is Kaspersky Total Security. It delivers excellent malware protection, a full complement of extra features and an easy-to-use interface.
Right behind that are Bitdefender Antivirus Plus, an entry-level program that may be the best bargain in antivirus software, and Norton 360 Deluxe, which offers excellent protection with unlimited VPN service and a ton of extra features, including the option to add LifeLock identity protection.
Any one of these three would serve you well, but the ideal choice would depend on what best fits your circumstances. For more, see our section on how to choose the best antivirus software below, or our stand-alone antivirus buying guide.
For the best free antivirus protection, we liked Kaspersky Security Cloud Free, which sailed past Bitdefender Antivirus Free Edition for the top spot.
Both offered excellent protection against malware without slowing down your system, but Kaspersky's free program lets you schedule scans, has a quick-scan option, adds a ton of useful extra features and had the smallest impact on system performance we've ever seen.
Our free rankings immediately follow our paid rankings below.
The best antivirus software you can buy today
Kaspersky's Windows products have excellent malware-detection scores and a light-to-moderate system-performance impact, the two most important criteria in our rankings.
The entry-level program, Kaspersky Anti-Virus (starting at £12.49 UK/$29.99 US), has dedicated ransomware protection, a virtual keyboard and a convenient online account portal. But it's beaten by Bitdefender Antivirus Plus, which has even more features.
Kaspersky Internet Security (£17.49 UK/$39.99 US) is our top choice among midrange packages. It has a secure browser, anti-theft protection for laptops, webcam protection and a limited-use VPN client that kicks in when you connect to an open Wi-Fi network. It also includes software for macOS, Android and iOS.
The premium antivirus suite, Kaspersky Total Security (£19.99 UK/$44.99 US), adds backup software, parental controls, file encryption, a file shredder and an unlimited password manager. We think it's the best antivirus software you can buy today.
As mentioned earlier, Kaspersky Total Security has won Best Antivirus Software in the 2021 Tom's Guide Awards.
Read our full Kaspersky Total Security review.
The best antivirus software you can buy
Kaspersky offers excellent malware protection, lots of useful extra features and a light system impact with an easy-to-use interface.
Bitdefender Antivirus Plus is our top choice among entry-level antivirus products. It has very good, if not perfect, malware-detection scores. Its active scans don't add much to the background system impact, but that background load is a bit heavy.
It also offers the most value, with an unlimited password manager, a secure browser with a virtual keyboard, a Wi-Fi network scanner, a file shredder, protection against encrypting ransomware and Bitdefender's new web-privacy software -- features often found only with pricier antivirus packages.
The midrange Bitdefender Internet Security adds parental controls, webcam protection and a two-way firewall, while Bitdefender Total Security tops off the lineup with an anti-theft feature for laptops, a system optimizer and licenses for Bitdefender Antivirus for Mac and Bitdefender Mobile Security for Android.
A fourth product, Bitdefender Premium Security, is basically Total Security with unlimited VPN usage and priority tech support. (The other programs limit you to 200MB of Bitdefender VPN usage per day.)
But the best deal is the Bitdefender Family Pack, which puts Total Security on up to 15 devices for (a frequently discounted) $120 per year.
As mentioned above, Bitdefender Total Security has merited a Highly Recommended mention for Best Antivirus Software in the 2021 Tom's Guide Awards.
Read our full Bitdefender Antivirus Plus review.
All nine of Norton's antivirus products offer excellent malware protection, and the once-heavy system-performance load is much lighter. The number of extra features each program has varies according to price, but the sweet spot in the lineup is Norton 360 Deluxe.
It includes a password manager, unlimited VPN service, dark-web personal-data monitoring, parental controls and up to 50GB of online storage space. Two retail-only offerings, Norton 360 Premium and Norton 360 Platinum, give you more online storage and expand the antivirus and VPN coverage to 10 and 20 devices, respectively.
If you want full-on identity protection, Norton offers three bundles with varying degrees of LifeLock service and even more online storage space. Their annual subscription prices run well into the triple digits, but still cost less than if you were to buy the identity protection, password manager, cloud-backup storage and antivirus software separately.
Unlike some of the other best antivirus software makers, Norton doesn't offer a file shredder, file encryption or secure web browser with any of its products. Yet every other digital-protection service you could possibly ask for is included with at least some of its bundles.
Read our full Norton 360 Deluxe review.
McAfee's malware detection has improved greatly in the past couple of years, but it's still not quite top-of-the-line.
Despite that, the entry-level McAfee AntiVirus Plus is a bargain: $60 per year buys software for up to 10 (in practice, unlimited) devices, whether they run Windows, macOS, iOS or Android, and the software comes with a file shredder and a two-way firewall.
McAfee Internet Security adds one of the best password managers in the business, but to get parental controls, you'll have to spring for McAfee Total Protection or its sibling McAfee LiveSafe, which comes pre-installed on many new PCs.
The multi-device licenses of those two security suites also come with an identity-protection service. But none of the McAfee products have a secure browser or webcam protection, which you often get with other premium antivirus programs.
At the top is McAfee Total Protection Ultimate, which adds unlimited VPN service with no strings attached. Hardcore PC gamers may consider McAfee Gamer Security, which for $60 per year offers low-overhead protection for a single rig.
Read our full McAfee Internet Security review.
Trend Micro offers very good protection, but its malware-detection engine creates a heavy system load during scans and returns a fair number of false-positive results.
The brand's entry-level program, Trend Micro Antivirus+ Security, has basic tools but does have a secure web browser. Parental controls, a system optimizer and a file shredder are bundled into the mid-range Trend Micro Internet Security.
Trend Micro Maximum Security adds a password manager, a secure browser and file encryption, while the new Trend Micro Premium Security adds a VPN and dark-web monitoring of personal data.
However, none of Trend Micro's programs include a two-way firewall or webcam protection, standard with other brands' midrange offerings. Nor does the premium product have the cloud storage or backup software that some of the best antivirus brands add as enticements to their flagship packages.
Read our full Trend Micro Maximum Security review.
ESET is one of the biggest antivirus names in Europe, with a very small system-performance load and fast scans. Its malware-detection rate used to be kind of meh, but has improved markedly in recent lab tests.
The entry-level ESET NOD32 Antivirus is easy to use, but has few useful extra tools. ESET Internet Security adds webcam protection, parental controls and a browser-hardening extension, as well as ESET security-software licenses for Mac, Android and Linux devices.
The top-billed ESET Smart Security Premium tosses in file encryption and a password manager. However, there's no VPN client, backup software or file shredder.
ESET's pricing is per device, which is optimal for users who might have more than a few devices to protect. But if your device count gets into double digits, ESET's costs can add up.
Read our full ESET Smart Security Premium review.
Sophos Home Premium does its job economically, offering reasonable protection from malware at an affordable price.
Because it's spun off from Sophos' enterprise software for business clients, Sophos Home Premium lacks many of the bells and whistles other security suites offer, such as a password manager, identity theft protection service or VPN service.
What Sophos Home Premium does have is the essentials: ransomware rollbacks, webcam defenses and protection against keyloggers, malicious websites and boot-sector and fileless malware. It also has a web-filter system for parents and an online management console from which you can tweak most of the settings.
Some people might demand more from an antivirus suite, but anyone who would rather buy only what they need will appreciate Sophos Home Premium's just-the-basics approach.
Read our full Sophos Home Premium review.
Best antivirus news and updates
— A jaw-droppingly simple flaw in Windows 10 and Windows 11 lets any local user or program seize control.
— Microsoft fixed 117 security flaws in the July Patch Tuesday updates, including nine "zero-days."
— Strange malware has been mysteriously wiping WD My Book external hard drives of data.
The best free antivirus software
A good paid antivirus suite is a digital-protection jackknife, often bundling in parental controls, identity theft protection, a password manager, backup software, cloud storage, a firewall, a system optimizer and software for Mac, Android and iOS as well as Windows.
But what if you just want Windows antivirus software without all of those pricey extras? And what if you can't afford to pay for antivirus software? One of the best free antivirus programs might be exactly what you need.
Free antivirus software used to be a step down and involved making some trade-offs. The protection wasn't as good, and you'd either have to put up with ads filling your screen or with constant nags to upgrade to a paid program.
Thankfully, that's all changed in the past few years. Two of the best antivirus makers, Bitdefender and Kaspersky, now offer free versions with the same excellent malware protections as their paid offerings. A merger between the biggest names in free antivirus, Avast and AVG, created a combined malware-detection engine that's much better than its predecessors.
Meanwhile, Microsoft's built-in antivirus software, Windows Defender, aka Microsoft Defender Antivirus, has gone from being a sad joke to being one of the best antivirus programs out there, free or paid.
You can now get free antivirus protection that's as good as anything you pay for. These are the best free antivirus programs based on their protection, system impact, ease of use and extra features.
What are the best free antivirus programs?
Kaspersky Security Cloud Free Antivirus may be the best free antivirus program we've ever seen. It has excellent malware protection, a decent set of extra functions and features, and a system-performance impact so small that our computer actually sped up after we installed the program.
Bitdefender Antivirus Free Edition is still the best "set it and forget it" free antivirus option. It takes care of itself and doesn’t need user intervention. If you need to put antivirus software on your grandparents' computer, or you'd rather not have to think about it at all, this is the perfect solution.
The sleeper here is Microsoft Defender Antivirus, aka Windows Defender, which is built into Windows 8.1 and 10. It used to be an embarrassment, but has rapidly improved to become one of the best antivirus programs. You don't have to install or download it — it's already on your PC.
If you want an unlimited password manager or a hardened web browser, Avast Free Antivirus might be for you. Its malware protection is much better than it once was, although its performance impact is fairly heavy.
Avast's stepsister AVG has the same malware-detection engine, but lacks Avast's full slate of useful extra features. But it does have a file shredder and system optimizer.
We have to mention one program that's not even antivirus software, but which we recommend anyway: Malwarebytes Free. While antivirus tries to stop malware from infecting your machine, Malwarebytes functions as the cleanup crew, sweeping out less-harmful adware or potentially unwanted programs that the antivirus software ignores. It works well alongside any antivirus program.
The best free antivirus software you can get today
Kaspersky doesn't talk much about its free antivirus product, and you might have a hard time finding the free Kaspersky software download page on the company's website.
That's too bad, because Kaspersky Security Cloud Free is the best free antivirus product we've ever tested. We've never seen such a combination of excellent protection and extra features in a free antivirus program.
It's got a bright, comprehensible interface, a lot of customization potential and Kaspersky's unbeatable malware protection. The program also lets you schedule scans, and its performance impact was so small that it actually sped up our test machine a bit.
Kaspersky's useful extra features include a file shredder, an on-screen keyboard and an email scanner. The password manager and VPN service are fairly limited, however, unless you pay.
Read our full Kaspersky Security Cloud Free review.
Compared to premium paid antivirus programs that are big, heavy and loaded with extra bells and whistles, Bitdefender Antivirus Free Edition is like a mid-'60's sports car, stripped to the essentials but still providing plenty of power.
Bitdefender Antivirus Free Edition offers nothing but the basics. There's no password manager, no gaming mode, no quick scans and no scan scheduling. You can manage the software from the program's System Tray icon, but you don't really need to interact with Bitdefender Antivirus Free Edition after installation.
Yet Bitdefender Antivirus Free Edition has the excellent Bitdefender malware-detection engine, which sits just below Kaspersky and Norton in the lab-test rankings.
It's the best free antivirus software if you want a security solution that you can set up and then forget about. It's also perfect if you need to protect the computer of an elderly relative but don't have time to manage antivirus software from afar.
Read our full Bitdefender Antivirus Free Edition review.
Microsoft's built-in antivirus software is now a heavy hitter. While Windows Defender doesn't quite beat Bitdefender or Kaspersky in malware-protection lab tests, it comes out ahead of Avast, AVG and most other free antivirus products while operating almost entirely behind the scenes.
You won't be getting many extra features with Windows Defender itself, yet Windows 10 does have parental controls, a gaming mode and protections for its own Edge and Internet Explorer browsers. There's no built-in password manager or VPN, but you also won't be bothered by pop-ups trying to upsell you to paid antivirus software.
We still recommend going for Kaspersky Security Cloud Free, which has even less of a system impact, better malware protection and more useful extras, but there's absolutely nothing wrong with using Windows Defender as your primary antivirus solution.
Read our full Windows Defender review.
Avast Free Antivirus has the best assortment of extra goodies of any free antivirus program, including an unlimited password manager, a hardened browser, a gaming mode, a Wi-Fi network scanner and a recently added ransomware shield.
The program is also very customizable, letting you tweak its appearance and functions to suit your style. It even offers limited access to Avast's VPN service.
However, Avast Free Antivirus caused a pretty heavy system load in our testing and its scans took a long time. It also kept nagging us to upgrade to Avast's paid antivirus protection, and played bait-and-switch with features that looked like they were free but weren't.
Most significant of all, the malware protection in Avast Free Antivirus is a peg down from Kaspersky's or Bitdefender's, whose free programs also bothered us less about paid upgrades and had lighter system loads.
Read our full Avast Free Antivirus review.
AVG shares a decent, if unspectacular, malware-detection engine with its corporate sibling Avast while having a much lighter system-performance impact.
But AVG AntiVirus Free also has far fewer useful extra features than Avast Free Antivirus. While the latter is almost a free security suite with lots of bells and whistles, AVG AntiVirus Free is the quiet, neglected child that gets the hand-me-downs.
The good news is that AVG's wide range of customization options and its file shredder and system optimizer are still available, and its interface is open and easy to use. The bad news is that like Avast Free Antivirus, AVG AntiVirus Free constantly bugs you to upgrade to paid antivirus software.
Worst of all, given its middling malware detection and dearth of extra features, there's no convincing reason to choose AVG AntiVirus Free over the built-in and overall better Microsoft Defender.
Read our full AVG AntiVirus Free review.
Malwarebytes Free, formerly called Malwarebytes Anti-Malware, is not antivirus software. Instead, it's a very useful malware-removal tool.
What's the difference? Unlike antivirus software, Malwarebytes Free can't prevent a PC from being infected. But it does an excellent job of cleaning out malware that's already on your system, as well as removing (legal) adware and potentially unwanted programs that antivirus software often ignores.
Malwarebytes Free doesn't interfere with any antivirus software that's already installed, so it's perfectly safe to install it alongside one of our recommended brands. (Just don't upgrade to the paid Malwarebytes Premium, true antivirus software that does poorly in lab tests and which will conflict with other AV programs.)
We recommend Malwarebytes Free as a complement to any of the best antivirus programs, free or paid.
Read our full Malwarebytes Free review.
How to choose the best antivirus software for you
Before you buy antivirus protection, figure out what you need. If you have young children at home, then consider midrange antivirus products, most of which include parental controls.
Do you want an all-encompassing security solution? Many premium products include identity-theft protection, password managers, backup software and/or VPN service.
Or are you a techie who understands and the risks of using the internet? Then a low-priced basic program might be all you need.
Once you've got your priorities figured out, then determine how many machines you'll need to protect.
Most vendors offer single-device licenses for Windows PCs. But multi-device, multi-platform licenses for five, 10 or more computers and mobile devices are available in midrange and premium antivirus packages, covering Windows, macOS, Android, iOS and sometimes even Linux. Some vendors offer plans that cover an unlimited number of devices.
Gone are the days when you could walk into a store and pay a one-time fee for an antivirus product that came in a box off a shelf. All the vendors now sell their software licenses as yearly (or multiyear) subscriptions. The upside is that you'll always get the latest software, which you can download and install straight from the internet.
Antivirus pricing and features
Many antivirus products are sold online for much less than their list prices. But each brand offers basic, midrange and premium configurations of features and pricing, with every step up adding more features.
Think of autos at a dealership. You can get a base-model car that will get you from place to place just fine. For a few grand more, you can buy a car with satellite radio, but no heated side-view mirrors, alloy wheels or in-car Wi-Fi hotspot. Or you can spend a lot more to get a loaded car with all the fixin's.
Antivirus makers also hope you'll spring for extra options, whether you need them or not. The one thing you can't trade up to is a bigger engine: All the Windows antivirus products in a given brand's lineup will use the same malware-detection engine and provide the same level of essential protection.
Basic paid antivirus software is usually just called "Antivirus" or similar, and yearly subscriptions start at $40-$60. The software will have essential malware protection and maybe a password manager or a two-way firewall.
Midrange antivirus software packages are frequently nameplated as "Internet Security" and start at $60-$80 yearly. They generally add parental controls, some of which are very good, plus a few other features such as webcam protection. They often include multi-device licenses and antivirus software for Mac and Android devices.
At the top are the premium "security suites," which toss in all the extra security tools an antivirus brand can offer, such as password managers, VPN client software, backup software, online storage and even identity-protection services.
List prices start at $80-$100 per year, but make sure you really need those extra tools you're paying for. The password managers are often quite good, but the online storage can be paltry and the VPN services often don't give you unlimited data.
We've collected the best premium antivirus packages on this list of the best internet security suites.
How we test the best antivirus software
Our evaluations are based on each antivirus program's interface, performance, protection and extra features. Was the interface intuitive and user-friendly? How badly did malware scans slow performance? How well did the program detect and remove malware? Does the program offer useful additional tools?
Most of our tests were performed on the same Asus X555LA laptop running 64-bit Windows 8.1 (later upgraded to Windows 10), with an Intel Core i3-4005U processor, 6GB of RAM and a 500GB hard drive containing 36GB of files.
Some of our newer performance tests were done on a Lenovo ThinkPad T470 with a 2.5GHz Core i5-7200U processor, 8GB of RAM and 256GB of solid-state storage containing 43.3GB of files.
To assess a program's impact on system speed on both Windows and macOS, we used our own custom tests, which measure how long a CPU takes to match 20,000 names and addresses on an OpenOffice or Excel spreadsheet. The longer it took the laptop to finish either test, the heavier the performance impact.
For malware-detection scores, we use the results of three independent testing labs: AV-TEST in Germany, AV-Comparatives in Austria and SE Labs in England. Each lab subjects the major antivirus brands' products to stress tests involving thousands of pieces of malware, including hundreds of previously unseen samples.
Editors' note: Why we recommend Kaspersky
Kaspersky antivirus products have been banned from U.S. government agencies and U.S. defense contractors, and we can understand why. Because the company is Russian and antivirus software can peer deep into a PC, using Kaspersky software would create an unacceptable risk for persons and organizations involved in national security and critical infrastructure.
However, we still think Kaspersky software is perfectly safe for home users. We've seen no evidence to convince us otherwise. Kaspersky researchers are well respected throughout the antivirus industry, and the company has publicly exposed Russian cyberespionage campaigns as well as those from the United States and other countries around the world.