Protecting your PC, laptop and even your phone from internet threats is essential these days. It's no longer optional.
Many people would rather not pay for the privilege and - since you're reading this - you probably fall into that camp. While there are great deals available on paid-for security suites, it still amazes us that you can have the same antivirus protection that's in Kaspersky's, Bitdefenders and other packages for free.
So, after reading through our list of six recommended options below, there's no excuse for not running antivirus software on all your PCs and laptops. With Avast and AVG's offerings you can protect your Android phone, Mac and iPhone too.
Should you get free antivirus?
The catch with free antivirus is that it doesn't always offer the most complete protection. It is better than having none at all but free versions tend not to include some of the extra features that come with paid-for products.
This is why using the term 'antivirus' can be misleading. Antivirus is typically just one component of a good security product, which can also include specific protection from ransomware as well as spam filtering, parental controls, password managers, VPNs and cloud storage. However, that's not to say those features can't be found in free products - you'd be surprised what you can get without paying or even handing over your email address.
If you want the comprehensive protection and support a paid-for version includes, you'll find recommendations in our best antivirus roundup.
Best Free Antivirus Reviews
Kaspersky Security Cloud Free
Kaspersky is a big name in antivirus, and it offers a free version for PC.
As you'd expect, this is pared-back offering compared to the paid-for version of Security Cloud.
There are no parental controls or online payment protection here and you don't get a password manager or VPN as with the paid versions. You can get free versions of the latter two anyway: read our free VPN and password manager roundups for recommendations.
Instead you get the core antivirus protection including file, email and web-based threats, automatic updates, quarantine and more.
What's particularly good to see included is the ability to scan a file by right-clicking on it, then send it to the Kaspersky Security Network to instantly have its reputation checked out.
You also have access to Kaspersky's cloud-based Application Advisor, which provides a full rundown about the content of the file, the number of users that have tested it, where in the world people are using it, along with various pieces of technical information.
In the independent SE Labs' latest report, Kaspersky came out top for protection (on Windows computers), which is especially reassuring.
There's also an Android version that includes antivirus protection for your phone, which scored full marks in AV-Test's most recent tests.
Avast Free Antivirus
Unlike some some AV companies, Avast doesn’t hide its free antivirus offering so you can’t find it. It's prominent on the website's homepage, more so than even its paid offerings, so that's a good start.
As well as basic protection, Avast Free Antivirus offers defence from unknown threats using its Behaviour Shield, which stops even previously well-behaved software from suddenly performing dodgy operations that could endanger your identity and data.
There's also a handy password manager, so you can log into sites in your browser by remembering just one password. This is pre-stuffed at installation time with login details found in your installed browsers.
The free version can also scan your Wi-Fi network and alert you of vulnerable devices or 'intruders'.
Finally, there's ransomware protection too, which is often reserved for paying customers.
Best of all, Avast Free Antivirus is top-notch at stopping malware: the three independent test labs we refer to all highly rate it with AV-Test giving it top marks across the board and SE Labs ranking it third for overall protection behind Kaspersky and McAfee (which doesn't offer a free version).
It's even available for Android, macOS and iOS too!
AVG AntiVirus Free
AVG is owned by Avast, so both free products use the same engine and have the same level of protection.
AVG's free offering has antivirus, ransomware, spyware and will stop other forms of malware.
AVG Antivirus Free offers six different scan types, including Deep Scan, USB/DVD scan, single file or folder scans, and a boot-time scan, which runs before Windows starts up, thereby running before any lurking malware has a chance to start up and protect itself from the product.
In addition to AV duties, AVG also warns you of unsafe web links, and can block unsafe email attachments. As the greyed-out tiles attest to, you're not getting the same level of protection as if you were paying for AVG Internet Security, but for free you can't complain.
And like Avast's free version, AVG's is available for Windows, macOS, Android and iOS.
Bitdefender Antivirus Free Edition
Bitdefender's free offering is simple, robust and reliable. Its paid-for version remains a great choice, but if you want basic antivirus protection for nothing, then Bitdefender also has you covered.
But by simple, we really do mean simple. There are no modules here that turn out to be paid versions, no password manager, and no secure browser to install. This is stripped back system protection only, offering just antivirus and nothing else. However, the antivirus engine is the same as the full version, so although you're not protected from a wider range of threats as with Bitdefender Total Security (pictured), this free offering will do the core job just as well.
The interface is sparse. You can drag-and-drop files on to it to scan them, but you can also right-click them in Explorer and do the same thing without dragging. Any dodgy files are quarantined, and you can also set up exclusions - both files and folders - that will not be scanned. This is useful if Bitdefender should produce a false positive that keeps preventing an application from running.
Overall, being stripped back to just the essential antivirus function, Bitdefender Antivirus Free Edition is very simple to use, with good AI-based protection. It's lightweight, too, so won't slow down your computer.
Bitdefender scored 100% for protection in AV-Test's most recent report and it only lost half a mark for performance because of an uncharacteristic slow down of the time it took apps to launch while running the software.
As well as a Windows version, you can also get Bitdefender Antivirus Free for macOS and Android.
Microsoft Windows Defender
Many people think Windows Defender isn't up to the task. It's part of Windows 10 and runs by default when no third-party antivirus software product is installed. But surely it can't be anywhere near as good as the expensive, paid-for security apps?
Wrong. In the latest SE Labs report, Windows Defender placed fifth overall, beating eight paid-for antivirus programs. AV-Test also found that it detects and protects against almost all attacks just as effectively as Kaspersky and others. Performance of any antivirus software varies from month to month, but it's still good to know that Defender does an excellent job, and that it's already protecting your Windows devices if you haven't installed any other security software.
There's a common perception that Windows Defender has no toys in the box beyond basic antivirus duties. This is not the case. For starters, there's ransomware protection that allows you to nominate folders that cannot be changed other than with your explicit say so. Integrated OneDrive support allows you to recover files that do become corrupted by malware.
You have to configure these - they're not enabled by default. But that's true of rival products as well.
Suspect samples can automatically be submitted for thorough cloud-based analysis. Being tightly integrated with Windows also allows Defender to provide innovative sign-in options, including Windows Hello, which allows you to log in with your face or fingerprint.
There's also the integrated Windows firewall, advanced exploit protection, and protection from code being injected by malware into innocent processes.
Secure Boot prevents rootkits or anything else from running and hiding before other software, including AV software, gets a chance to start up. Scanning duties include an offline scan that runs at boot time, before Windows starts, thereby denying rootkits and other stealthy malware a place to hide.
Bottom line: you could do a heck of a lot worse than Windows Defender.
Avira Free Security
Avira is a German company which has offered free antivirus software for as long as we can remember.
There's a paid-for version called Avira Prime, but the free version uses an identical malware detection engine which has previously received top marks from two of the big virus testing houses: AV-test.org and AV Comparatives. In the most recent report from the UK's SE Labs it didn't fare as well, achieving a slightly worse overall protection rating than Windows Defender.
Like certain other free offerings, Free Security appears solely designed to nag you into upgrading to Prime. We much prefer Bitdefender’s approach of a stripped-back app that doesn’t pretend to be a security suite.
It's nice that you don’t have to hand over any personal information at all - not even an email address - which is rare in this day and age. Avira clearly states on its website that it doesn’t sell data and never will.
There's also a Mac version, reviewed on our sister site Macworld, plus Android and iOS versions so you can protect all your devices for free.
Is free antivirus really free?
Yes it is. But you may well trade off some privacy. For example, Avast and AVG’s privacy policies clearly explains how it uses your personal and non-personal information when you download and use its free product.
You might be asked if you want to opt in to data collection during installation of these products. This is why it is absolutely crucial you read what you're agreeing to when you install an app, and are extra careful to opt out of any data sharing.
Otherwise, you grant the software the right to share some of your (anonymised) information to third parties, which may include advertisers and other companies.
The danger is that a company might work out how to de-anonymise this data, which is a risk you don't want to take.
And some free antivirus products will be supported by adverts, typically on Android versions. You can find out if it's worth installing antivirus on Android and whether iPhones need protecting from malware or not.
And these days, antivirus software should comply with GDPR in Europe and with other privacy regulations in other countries.
Does free antivirus software work?
Privacy is perhaps not the most important factor, depending on your outlook. Antivirus software is designed to prevent your PC and laptop - plus phone and tablet - from being infected by malicious code which could cause issues ranging from annoying pop-ups through to stealing your personal information or even deleting or encrypting your files.
The effectiveness of antivirus software changes over time, and a product that stops all viruses today may not do that tomorrow or in a month. No antivirus software offers a cast-iron guarantee that it will stop 100% of malware, but many achieve this figure. And it's essentially the same virus protection you get from the paid-for version of that product.
So, yes. It works. It's not an excuse to start downloading cracked software or visiting dodgy sites though. Security requires a multi-layered approach, and that includes being careful and sensible about the sites you use, the links you click on and the stuff you download.