AVG Signal Blog Security Viruses The Best Free Antivirus Software for 2021
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Top picks:

  • Avast Free Antivirus

  • AVG AntiVirus FREE

  • Avira Antivirus

  • Bitdefender Antivirus Free Edition

  • Kaspersky Security Cloud Free

  • Microsoft Windows Defender

  • Sophos Home Free

Additional options

  • Adaware Antivirus Free

  • Check Point ZoneAlarm Free Antivirus+

  • Qihoo 360 Total Security

Read on for a quick summary of the best choices for free antivirus software for 2021.

Avast Free Antivirus

One of the oldest antivirus companies, Avast has been protecting people since 1988 and is trusted by more than 400 million users around the globe. Avast secured PCMag’s coveted Editors’ Choice designation in 2021.

01-icon-Essential-protectionEssential protection: Avast Free Antivirus consistently ranks extremely high for its core virus protection engine and malware removal tools. Top antivirus test lab AV-Comparatives named Avast Product of the Year in 2018 and Top-Rated Product in 2019 and 2020, in addition to giving Avast awards for Real-World Protection and Advanced Threat Protection. Avast continues to support Windows 7, even though Microsoft has stopped updating that operating system.

02-icon-FeaturesFeatures: Offering an easy-to-use interface, a secure web browser, a network security scanner, and more, Avast has a wide range of useful bonus features. Lifewire praises its Do Not Disturb Mode, which blocks pop-ups while you watch movies or play games. Lifewire also highlights the Behavior Shield, which keeps an eye on your apps to make sure they don’t start acting strangely, a potential sign of a malware infection.

03-icon-Second-opinionNeed a second opinion? TechRadar notes that “Avast has plenty of protective power and a bunch of extras, and does a good job of keeping you safe,” with protection results of 99.7% and 100% in various tests.

Download Avast Free Antivirus

AVG AntiVirus FREE

One of the pioneers of free antivirus software for Windows, AVG has consistently won awards from AV-Comparatives over the past decade — including Top-Rated Product in their most recent test.

01-icon-Essential-protectionEssential protection: PCMag praises AVG AntiVirus FREE for achieving strong scores in a variety of independent tests, and for its excellent protection against phishing. AVG’s on-demand virus scanner searches for hidden malware, which includes viruses as well as other sneaky malicious software such as spyware and ransomware. AVG AntiVirus FREE is simply one of the best free malware removal tools available.

AVG scans for malicious URLs, unwanted browser add-ons, and PC performance issues. AVG protects against zero-day threats by preventing unknown (and potentially dangerous) files from opening, and then sending those files to AVG’s Threat Labs team for deeper analysis. If they’re found to be malicious, a cure is created and pushed out to you and the entire AVG community.

It’s worth noting that AVG continues to provide the best antivirus software for Windows 7, even though Microsoft is no longer supporting that older operating system.

02-icon-FeaturesFeatures: AVG AntiVirus FREE offers several bonus features, including a free File Shredder to securely delete sensitive files and prevent your personal data from being exposed. PCMag notes that although AVG scans to find junk files and clutter that are slowing down your device, you’ll need AVG TuneUp to fix those problems.

03-icon-Second-opinionNeed a second opinion? In its review of the best free antivirus software for PC, Mashable notes that AVG AntiVirus FREE has the most accurate antivirus protection and malware detection, saying, “AVG AntiVirus FREE is near flawless with its ability to detect viruses and malware. It's unlikely anything is getting through this.”

Avira Antivirus

Avira has been creating antivirus applications for a long time, with the first one dating back to 1986.

01-icon-Essential-protectionEssential protection: While PCMag awarded Avira Antivirus a solid score in their malware blocking test, they also found the on-demand scan slow and cautioned that its “real-time protection missed some malware EXEs and identified some valid programs as malware.”

02-icon-FeaturesFeatures: Tom’s Guide notes that “many of Avira’s extra features are really trialware,” meaning you’ll be asked to pay for them after a short trial period. Plus, there’s a “heavy impact on system performance.”

03-icon-Second-opinionNeed a second opinion? SafetyDetectives says that “Avira’s free plan offers the same powerful antivirus engine as the premium version... The biggest downside is that you don’t get access to email or phone customer support, only the FAQ page.”

Bitdefender Antivirus Free Edition

Bitdefender protects millions devices around the world and is consistently recognized by independent test labs like The Independent IT-Security Institute.

01-icon-Essential-protectionEssential protection: TechRadar praises Bitdefender’s “clean, light, well constructed scanning mechanisms – which are almost universally faster than the industry average – and unrivalled virus definitions.” But they also note that the product doesn’t offer many customization options and has “a few flaws in its handling of zero-day threats.”

02-icon-FeaturesFeatures: PCMag says that “Bitdefender Antivirus Free Edition includes the core malware-fighting components of Bitdefender's commercial edition, but without the vast collection of additional security features, and without some advanced layers of malware protection.” CNET notes that “Bitdefender Antivirus Free is refreshingly free of the ‘extra’ features and tools that make some apps unwieldy and confusing.”

03-icon-Second-opinionNeed a second opinion? DigitalTrends mentions that “the application features no configurations of any kind,” while TechNadu adds that Bitfender is “missing extras” but “good for those who have entry-level computers.”

Kaspersky Security Cloud Free

Russian cybersecurity firm Kaspersky has faced allegations of inappropriate connections to the Kremlin, prompting the US, the UK, and the Netherlands to ban the use of Kaspersky products across government agencies. Nevertheless, the allegations remain inconclusive, and Kaspersky is consistently a top-rated antivirus product.

01-icon-Essential-protectionEssential protection: Kaspersky Free has earned strong marks in independent test labs, including good scores on PCMag’s malware- and ransomware-blocking tests as well as on their phishing test.

02-icon-FeaturesFeatures: According to SafetyDetectives, “Kaspersky’s free antivirus provides good real-time malware protection, but its additional features are very limited.”

03-icon-Second-opinionNeed a second opinion? TechRadar says that Kaspersky is “one of the best and most accurate antivirus engines around,” but “doesn’t have the extras to match some of the competition.”

Microsoft Windows Defender

Windows Defender is Microsoft’s built-in free antivirus for Windows 10. If this app is already on your PC, you might be wondering why you should even bother with a free third-party antivirus solution. The short answer is that many experts say Windows Defender simply isn’t as good as the best free antivirus programs.

01-icon-Essential-protectionEssential protection: While Windows Defender traditionally ranked below third-party antivirus software, it’s now improved enough to claim the number seven slot on PCMag’s annual top ten list. Its malware detection capabilities have improved, and it performed well in hands-on testing. Still, PCMag gives it a rather lukewarm review:

Windows Defender is improving, but you still shouldn’t rely on Windows 10’s security tools as your sole means of protection. Many free third-party apps are more effective at keeping you safe. — Neil J. Rubenking, PCMag Best Free Antivirus Protection for 2021

02-icon-FeaturesFeatures: Windows Defender still lags behind in phishing protection and malicious URL blocking, and it can’t compete with the extra security features included in most free third-party security software. 

03-icon-Second-opinionNeed a second opinion? Tom’s guide says that Windows Defender offers “very good malware protection,” but lacks “easy-to-schedule scans, a fair number of extra goodies, lots of customization options and a superlight system load,” which you can find with many of the best free antivirus options for Windows 10.

Note for Windows 7 users: Microsoft's built-in antivirus for Windows 7 is Microsoft Security Essentials. The company will continue to support the antivirus software for the time being, but their overall support for Windows 7 has ended, and they recommend you upgrade to Windows 10. If you keep Windows 7, it’s more important than ever to protect your system with strong third-party antivirus software.

Sophos Home Free

Sophos Home Free offers much of the same protection as Sophos’s business products, including remote security management for up to three PCs or Macs. That means you can also install the free antivirus software on a less tech-savvy family member’s computer and remotely manage their security for them.

01-icon-Essential-protectionEssential protection: PCMag reports that Sophos achieved excellent scores in their hands-on tests and excellent protection against malicious websites. But unlike the other major players on this list, Sophos has few independent lab test results to prove its efficacy. Sophos also received a poor phishing protection score from PCMag. 

02-icon-FeaturesFeatures: While the remote security management tool is a unique feature in a free antivirus program, Cloudwards cautions that, “The bottom line is that Sophos Home Free is lacking too many features to be worth it.”

03-icon-Second-opinionNeed a second opinion? According to TechRadar, “Sophos Home Free is an interesting product, simpler than most competitors and with handy central management of all your device security. It's extremely short on features, though, and we'd like to see more coverage from the testing labs, too.”

Additional options

While the other popular free antivirus programs didn’t rank the highest this year, you may be wondering how some of these other programs fared in expert reviews. So here are few more antivirus products to consider:

Adaware Antivirus Free

Adaware Antivirus Free comes from Adaware, formerly known as Lavasoft. 

01-icon-Essential-protectionEssential protection: Adaware Antivirus Free has received mixed scores in past independent tests, and PCMag cautions that Adaware has no recent test scores to show. Plus, their product received low scores in PCMag’s hands-on tests, and it provides no protection against malicious or fraudulent URLs.

“If you’re going to replace the antivirus built into Windows with a third-party free solution, you want one that will beat the OS's integrated protection. Unfortunately, Adaware Antivirus Free doesn’t meet that standard,” says PCMag.

02-icon-FeaturesFeatures: Adaware’s free antivirus lacks features found in other free products — including the company’s own previous edition. TechRadar adds that “most features are very basic.”

03-icon-Second-opinionNeed a second opinion? AntivirusReview says, “if you’re looking for the best possible antivirus software, then you’ll be better off with a different product. We’re not saying that Adaware is worthless — far from it. Still, objectively, it is not as strong in lab tests as we’d like it to be. And for an antivirus, protection should always be the #1 concern.”

Check Point ZoneAlarm Free Antivirus+

Check Point ZoneAlarm is a free antivirus-firewall combo that licenses its antivirus engine from security giant Kaspersky. 

01-icon-Essential-protectionEssential protection: Pairing strong antivirus prevention with a firewall can be good enough for basic computing. But TechRadar bemoans the lack of comprehensive threat protection, noting that ZoneAlarm is missing “web and email monitoring, network file scanning, and real-time cloud protection to keep you safe from the very latest threats…. These aren’t restrictions we’ve often seen in other free antivirus apps.”

02-icon-FeaturesFeatures: Unfortunately, this free cybersecurity solution is missing many features you would expect to see, such as web-based security, protection against malicious websites, and personal data protection. “It lacks some antivirus features [and] some of its bonus features don’t work,” says PCMag.

03-icon-Second-opinionNeed a second opinion? Cloudwards comments that “the protection you receive on the free tier is solid and reliable,” but “the best features are locked behind the paid tiers.” Cloudwards also notes that ZoneAlarm is becoming outdated, and “could now badly use an update to its interface as well as a new round of security testing.”

Qihoo 360 Total Security

Qihoo is a Chinese company known for its antivirus software, web browser, and mobile app store.

01-icon-Essential-protectionEssential protection: Qihoo formerly used the same core antivirus as Bitdefender and Avira, but it no longer does. Sadly, its malware protection has suffered for it. PCMag reported poor scores on their anti-malware, ransomware, and malicious URL blocking tests, and rated Qihoo’s anti-phishing performance “terrible,” calling it a “phishing protection failure.” They also note that Qihoo hasn’t been reviewed by the major independent antivirus test labs in years, which should raise your embrows.

02-icon-FeaturesFeatures: Qihoo comes with an impressive suite of bonus features, including cleanup and tuneup utilities, an adblocker, and more.

03-icon-Second-opinionNeed a second opinion? TechRadar says, “There are loads of features on offer, but most are below-par, and 360 Total Security isn't accurate enough to be your sole antivirus app.”

Disqualified options

You may have been expecting to see some big-name antivirus players on this list, like Norton, McAfee, or Malwarebytes. For various reasons, they didn’t make the cut. Here’s why.

  • Norton offers only paid antivirus software. Though they have a 30-day free trial, it’s not enough to earn a spot on our best free antivirus software list.

  • McAfee is the same as Norton — a free trial, but no free version. So, they just can’t compete on our best free virus protection list.

  • Malwarebytes doesn’t offer a traditional free antivirus. Their free protection tool is adept at detecting and removing malware from your PC, but Malwarebytes doesn’t offer real-time antivirus or malware protection. You can find this in their paid products, but why not go with a full-service free option instead?

FAQs

Why do I need antivirus protection?

You can avoid some forms of malware by practicing smart digital habits like using secure messaging apps and checking that websites are safe before you use them. But hackers are craftier than ever. Social engineering tricks, phishing scams, malicious URLs and infected downloads… the list goes on. 

Cybercriminals find ways to reach even the most careful among us. And with advanced cybercrime techniques like ransomware, once you get infected it’s too late. That’s why you need an extra line of defense in the form of an antivirus. Make sure to choose one of our best security software options with robust protection against all kinds of online threats.

Mobile devices may also be susceptible to malware, so protect yours with a security program that can remove malware from your smartphone.

How should I choose the best antivirus?

When it comes to the best virus scanners and best anti-malware tools, there are tons of choices. Here’s what you should consider before downloading your antivirus solution:

  • Effectiveness: Of course, the most important factor is how effective the antivirus engine is against malware and other threats. Gone are the days when the primary internet baddie was the computer virus. Today, you’re more likely to face ransomware, phishing scams, malicious URLs, and other sneaky internet dangers. Look for antivirus software that protects against the full spectrum of threats while offering real-time protection so there’s never a lapse in your defenses.

  • Impact on system resources: No one wants an antivirus that slows down your PC. Check to make sure the software you’re downloading has a light system load and minimal impact on your normal computer experience. This is especially important if you’re into optimizing your gaming machine.

  • Costs and discounts: This isn’t a list of the best paid antivirus software, and for good reason: there are a great many high-quality free antivirus programs that can keep your PC and your sensitive personal data protected. There’s no better discount than free, right? We recommend starting with one of the strongest best free internet security options above.

  • Privacy: Antivirus programs need access to all parts of your machine to properly protect it. That means you should choose a program from a reputable developer with a reasonable and transparent privacy policy.

  • Protection for other platforms: You’ll find many options for the best Windows 10 antivirus above. But you probably have additional devices, right? Malware, phishing, and other threats also affect Macs, Androids, and even iPhones. Some companies offer multi-device subscriptions so you can easily protect yourself with free antivirus software for Mac, cybersecurity for Android, and mobile security for iOS.

Why is free protection enough? Free vs. paid antivirus software

As they say, there’s no such thing as a free lunch… but there is such a thing as quality free antivirus software, and our list is full of them. Most companies offer advanced features, add-ons, and customization options in their paid products. But our above list of the best free programs contains options for excellent virus and malware protection — and many include great features in their free versions, too. Free antivirus protection is ideal for those who want to stay protected, but don’t necessarily want to tinker around with advanced settings or tons of extras.

Why isn’t Microsoft’s Windows Defender good enough?

Microsoft has put resources into trying to make its built-in solution the best free antivirus for Windows 10. But while it has improved by leaps and bounds in recent years, Windows Defender is still not as good as many third-party options out there, like AVG, Avast, Kaspersky, and BitDefender. Windows Defender’s results from independent test labs, while good, don’t always reach the level of those antivirus mainstays.

Beyond test results, there may be other issues with relying solely on Windows Defender. In multiple instances, Microsoft’s own updates have caused bugs and/or disruptions in Defender’s antivirus protection. But should you skip Microsoft’s updates to make sure its antivirus can run unhampered? Absolutely not.

Product and OS updates often include patches that plug security holes. Ignoring security updates can make you far more vulnerable to malware. Just ask the hundreds of thousands of people who got infected with WannaCry, despite Microsoft issuing a security update that would’ve fixed the problem weeks before the infamous attack hit.

And while Windows Defender protects against phishing attacks when using Microsoft Edge, it won’t cover you in other browsers. With these persistent limitations to Defender, most AV experts still recommend you opt for one of the best free anti-malware software options on our list above.

How are antivirus programs tested?

There are four major independent institutes that conduct antivirus testing and report independent test results: AV-Comparatives, AV-Test Institute, SE Labs, and MRG-Effitas. These labs have the resources to test thousands of real, active malware samples of all kinds (viruses, worms, ransomware, zero-day exploits, Trojans, botnets, backdoors, and more) and to perform the same tests on different antivirus software simultaneously to guarantee accurate comparisons.

These labs are certified by independent auditors, and many work with universities to ensure state-of-the-art testing methodology. Independent test labs charge the antivirus companies to participate in these tests. Major AV brands consider this a necessary expense in order to verify the efficacy of their product. So when a company has no recent test results to show, it might understandably arouse suspicion.

Well-known reviewers, such as Neil J. Rubenking of PCMag, use a combination of independent test results, their own hands-on testing, and their personal experience with a product’s usability and bonus features to judge the best antivirus software.

How will antivirus software affect the performance of my Windows computer?

A good antivirus solution will not slow down your computer. The top free antivirus software is designed to minimize its impact on your system. Make sure to select a program with light system load so you can stay protected but still use your computer exactly as you normally would.  

Note that an antivirus program’s impact on your system isn’t the same as how many notifications the program sends you. If you also don’t want to be disrupted with notifications, consider an antivirus with flexible options, such as AVG AntiVirus FREE’s Do Not Disturb mode. It’ll silence all notifications while you’re busy gaming, watching a movie, or using other apps that require your focus.

Protect yourself now with an antivirus trusted by millions

Don’t wait until it’s too late to secure your PC against viruses and malware. These days, it’s more important than ever to guard against viruses, cybercrime, and other emerging threats. Protect your sensitive personal information and your Windows PC with a strong antivirus tool.

With AVG AntiVirus FREE, you’ll get real-time security updates and 24/7 protection, so you can stay safe while browsing, emailing, and downloading files. Get the best free antivirus for Windows today for an impenetrable layer of defense against malware and other invasive digital threats.

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