Updated: Best free antivirus software 2016

Introduction

Our best free antivirus round-up has been fully updated.

Staying loyal to the trusty built-in Windows Defender keeps you safe to a certain extent, but with independent testing showing it typically misses at least one threat in 10, you really should look elsewhere.

Your Android device has stronger core security, but it's still vulnerable to the new crop of malicious apps, and you're going to need some help to stay safe.

Luckily paying through the nose for this type of protection is no longer the status quo and there are scores of different free programs offering protection that is more than adequate.

So if you no longer want to pay for the privilege of protecting your valuable piece of hardware, read on – we've picked out four of the best free antivirus engines, two top Android apps and three online detection services, all delivering great security at no cost.

• Also check out: Best antivirus 2016: 10 antivirus packages reviewed and rated

AVG AntiVirus Free

While AVG struggled to keep up with the competition for most of last year, you shouldn't give up on the package just yet – the latest AVG engine is showing real signs of improvement.

Independent testing lab AV-Test recently awarded AVG AntiVirus Free its maximum score for protection, for example. AV-Comparatives isn't quite as impressed, but also has AVG climbing the rankings, often without delivering a single false positive.

The program is hugely configurable. You're able to define exactly what various scan types do, schedule them to run unattended, configure which notifications you'd like to see, decide how updates will be handled, and a whole lot more.

All this functionality is easily accessed, too, thanks to a well-designed interface which clearly points you to the features you need.

There are some issues. In particular, AVG AntiVirus Free doesn't get priority real-time updates, leaving you a little more vulnerable to the latest threats. But it's still a solid and reliable product, and the best AVG release for a while.

Avast Free Antivirus

While free antivirus software won't cost you anything to download, you might sometimes find you'll pay in other ways. Install Avast Free Antivirus and it'll also equip your PC with Google toolbar, unless you're paying attention and clear the relevant checkbox.

Once you're up and running, the situation improves rapidly, with Avast Free's clean and configurable interface giving speedy access to a host of features.

The testing labs currently award Avast only mid-range scores for its standard protection. But the package does better than most when blocking malicious URLs, which means you're less likely to encounter malware in the first place. And it also rates highly when dealing with tricky zero-day threats, another vital area where others often fall short.

Perhaps the real highlight here is the lengthy list of genuinely useful security extras. In a few seconds the program can warn you of network vulnerabilities, highlight missing software patches, reveal weak or duplicate passwords stored by your browser, and more.

Avast Free Antivirus doesn't offer the best antivirus protection, then, but a capable set of supporting tools mean it's still worth a look.

• For those looking for something beefier to protect their devices, check out Pro Antivirus 2016 from Avast, which sells for £27.72 on Amazon and comes as a one-user, two-year subscription with a myriad of features (remote assistance, rootkit protection etc).

Avira Free Antivirus 2016

Some security companies spend a great deal of time and effort on interface design, but Avira isn't quite so concerned. Avira Free Antivirus looks plain, ordinary, and a little dated.

Fortunately that's because the company is way more interested in substance than style, and the end result is one of the best security freebies around.

The product's engine is loved by the testing labs, scoring very highly in most tests. AV-Comparatives has placed it first in three out of the last 10 Real-World Protection Tests, and in the top five in five others. Panda has the only comparable free antivirus offering.

If you're looking for an easy life then you can leave the program alone, and it'll do its work almost entirely automatically. But expert users get plenty of fine control. There are options to protect the Hosts file, block autorun, scan archives, monitor network drives, set the file types to be scanned, even password protect your Avira installation so others can't mess with your settings.

Put it all together and Avira Free Antivirus is an excellent product which leaves most of the commercial competition trailing in its digital wake.

• While Avira free antivirus does the job, its bigger brother, the Ultimate Edition Suite 2015, might be a better bet with support for up to three devices for three years. You also get Laplink PCMover Express, DriveLock Private, SuperEasy Driver Updater and Avira Antivirus Pro for Android thrown in for a grand total of £39.90 at Amazon.

Panda Free Antivirus 2016

Panda Free Antivirus 2016 has to be installed with care: it'll set your browser's home and search pages to Yahoo unless you clear the necessary check boxes.

Fortunately Panda's accuracy means it's all worth the effort. The package almost always rates a top 5 place in AV-Comparatives' Real-World Protection Tests, and it's usually in the top 3, trampling all over most of the commercial competition.

URL filtering is another significant plus, with Panda doing an above-average job of blocking access to malicious sites.

Bonus extras include USB Protection to keep your USB keys safe from some malware, while Process Monitor is a Task Manager-like tool, displaying running processes, their open HTTP connections, and highlighting likely dangers.

If you're feeling picky, and spend long enough exploring the program, you might find one or two minor issues. Scanning speeds were marginally below average in our tests, for instance. And it's not as configurable as some of the competition.

It's hard to complain about a package which gives you market-leading protection at zero cost, though. If you're looking for something simple and reliable, which you can install and just leave to do its job, then Panda Free Antivirus is a great choice.

• Although Panda Antivirus Free is a superb deal, you can get the Global Protection (2016 edition) version (which includes Mac protection, VIP services, chat support as well as identity and family protection) for five computers for only £22.99 at Amazon.

Avira Antivirus Security 4.4

Selecting the best free Android antivirus app is difficult at the moment. It's a competitive market, and the independent testing labs currently show there's very little between the leading products.

Avira Antivirus Security earns our vote for its consistency. It's a reliable engine, typically amongst the top-rated apps at AV-Test and AV Comparatives (4.4 star rated at Google Play), and Avira's excellent record with PC products makes us think you'll be able to trust the product over the long term.

There are plenty of bonus features, too. Anti-theft tools can locate a lost phone, trigger a siren, remotely lock or wipe a device. Privacy ratings give you an indication of how apps are handling your data, and there's identity protection, app locking, call filtering and more.

Browsing protection, hourly updates and tech support are reserved for the commercial Pro version only, but Avira Antivirus Security provides the core essentials you need and does a great job of keeping you safe.

• While Avira free antivirus does the job, its bigger brother, the Ultimate Edition Suite 2015, might be a better bet with support for up to three devices for three years. You also get Laplink PCMover Express, DriveLock Private, SuperEasy Driver Updater and Avira Antivirus Pro for Android thrown in for a grand total of £39.90 at Amazon.

360 Security - Antivirus FREE

360 Security - Antivirus FREE is one of the most popular antivirus apps around – it's 4.6 rated in the Play store – and the name alone gives you one reason why: it really is free. Okay, you get ads, but there are no "upgrade" buttons or limitations to the protection you receive.

There's a lengthy list of extras. The optimisation features alone – junk file cleaning, memory booster, power saver – are more capable and effective than many standalone apps.

We're particularly interested in the antivirus, and 360 Security - Antivirus FREE delivers there too. It's an extremely accurate engine which doesn't generate too much traffic, significantly drain the battery, or otherwise get in the way of your regular activities.

The system also monitors apps as they're installed, blocking malware before it can do any harm, and there's a good set of bonus features: anti-theft, call and SMS filtering, an app locker and more.

VirusTotal

Installing a good antivirus engine will keep you safe from most threats, but no product offers a 100% detection guarantee. Even if a download hasn't raised an alert, you might sometimes wonder if it's safe.

Upload a suspect file to VirusTotal and eventually (it can take a while, especially at peak times) you'll see the scanning results from 50+ leading antivirus packages, along with an in-depth analysis of the file, and even what it does when run on your computer (the modules it needs, the files it reads and writes, and more).

One problem with this multi-product approach is you'll regularly see false positives, where most of the engines say a file is safe, but a few flag it as dangerous. If only a small number of packages raise alerts (maybe five or less), and the most trusted engines say it's safe, we may run the file anyway – but that does increase your risk of infection.

Wait a day or two and try scanning the file again, if you're concerned, or try a behavioural monitor like Payload Security (which we cover at the end of this round-up).

Metascan Online

VirusTotal is the king of the online virus scanners, but there are some competitors around, andMetascan Online is one of the best.

The core idea is much the same. Point Metascan Online at a file, it'll be uploaded and scanned by a host of antivirus packages, with their verdicts listed in a detailed report.

MetaScan Online uses less engines than VirusTotal – it employs 43 compared to 50+ – but that's not necessarily a bad thing. Dropping the weaker products should mean fewer false positives, and we also found reports were usually generated in less than a third of the time (there's none of VirusTotal's "your file is now queued...").

MetaScan Online can also scan marginally larger files than VirusTotal (140MB versus 128MB), and has a neat Scan History page to show how a file's detection rate has changed over time. But balancing that, it doesn't provide any behavioural information, and malware doesn't normally arrive in such large files anyway.

Overall, VirusTotal is still our online favourite, but MetaScan Online has pluses too. Give it a try, see how the site works for you.

Payload Security

Antivirus engines typically detect threats by matching files with malware signatures, which is great for known threats, but a problem if you run into something brand new and undiscovered.

Payload Security is an online service which doesn't use signatures, instead analysing application behaviour for malware-like actions.

This can take a very long time – we often waited five minutes or more – but the finished reports are hugely detailed. You'll read about malicious indicators in the EXE structure, packer types, the functions being used, DNS or website requests, modules loaded, files opened, image strings and a whole lot more.

Yes, this is just as technical as it sounds, but fortunately an overall "Threat Score" (out of 100) and a Yes/No "Malicious" indicator give you a clear verdict on the file. And although this isn't as reliable as VirusTotal for known malware, we found it much more likely to spot brand new threats.

For most cases we'd stick with VirusTotal, then. But if you're particularly suspicious of a file, and don't mind a lengthy wait for the report, Payload Security is a useful second layer of defence.