Many Windows users believe they don't need to pay for antivirus software, and most Mac and Android users think they don't need protection at all. It's true that Windows' much higher profile makes it the biggest target, but OS X and Android are just as vulnerable to malware.

It's worth paying for Windows antivirus software, because even the best free software leaves out features we consider essential. (Many antivirus products are sold online for much less than their list prices.) Mac and Android users have other options; our favorite Mac AV product costs nothing, and most Android security apps have free versions.

How We Tested

Our evaluations were based on a number of different criteria: interface, performance, protection and extra features. Was the product's interface intuitive and user-friendly, or did it make it too hard to find important tools? How much did scans slow down the computer's performance? How good was the program at detecting and removing malware? Does the program have any additional tools, and are they useful?

All of our tests were performed on the same Asus X555LA laptop running 64-bit Windows 8.1, with an Intel Core i3 processor, 6GB of RAM and a 500GB hard drive containing 36GB of files. To assess a program's impact on system speed, we used our custom OpenOffice benchmark test, which matches 20,000 names and addresses on a spreadsheet. The longer it took the laptop to finish the test, the heavier the performance impact.

For malware-detection scores, we turned to two independent testing labs, AV-TEST of Germany and AV-Comparatives of Austria. Each lab regularly subjects the major antivirus brands' flagship products to stress tests involving hundreds of previously unseen pieces of malware, with AV-TEST adding 20,000 instances of known malware. We used AV-TEST's results from the second half of 2015 and AV-Comparatives' evaluations from September and October 2015.

Windows Antivirus Software Types

Most antivirus makers have three tiers of Windows products, with each price bump adding extra features, such as child protection or cloud backups. But since each company uses a single malware-detection engine for all its Windows antivirus software, the cheapest item in any product line usually finds malware just as thoroughly as the priciest.

Not all users will need premium suites, or even midrange products. If you don't have kids, or if you already have cloud storage, the basic product may be enough.

Basic or Entry-Level Windows Antivirus

The least-expensive paid Windows antivirus products, which generally list from $40 to $60 per year depending on the number of PCs covered, have the essentials. Definition updates and scans are automatic; websites and email attachments are screened, and the products should be easy to use. Some basic AV programs toss in extra features, such as file shredders or system optimizers, that are normally found in pricier products.

Midpriced Windows Antivirus

These products list from $60 to $80 per year. They generally build on the basic packages by bundling in parental controls and a two-way firewall to catch outgoing data, although many add other features. But for the full feature set, you'll have to pony up for the premium products.

Premium Windows Antivirus

Top-tier packages are often called suites because they do much more than catch malware. They might also have file encryption, secure online storage, a password manager or an ad blocker. As most cover multiple devices, they also frequently bundle in Mac and Android protection. For all this, you're meant to pay between $80 and $100 per year — but as with all paid antivirus software, discounts can often be found online.

Free Windows Antivirus

Free Windows antivirus products usually offer only bare-bones protection. Malware updates and scans must often be manually initiated, and there's little protection against malicious websites or email attachments. We can recommend some free Windows antivirus software, but don't rely on Microsoft's own products (Windows Defender/Microsoft Security Essentials). They simply don't catch enough malware.

Mac Antivirus

Despite what Apple's marketing has historically implied, Macs do get infected, and the amount of Mac malware has risen with Apple's share of the personal computer market. But there's less money in the Mac antivirus market, and the products are less standardized. Some Mac antivirus products are free, and some are paid: Of the products we evaluated, two of the top three were free. With that kind of recommendation, there's no reason for you not to run antivirus software on your Mac.

Android Antivirus Apps

Every Android device, whether smartphone, tablet or TV stick, should have antivirus software. Usually, that software comes with an all-encompassing security app that also includes anti-theft and remote-locating features.

The free versions of the Android security apps we reviewed are pretty solid. The paid versions, which cost between $15 and $30 per year, range from being just a bit better to becoming practically separate products, with a wide range of capabilities. For example, Avast Mobile Security offers geofencing and, for rooted phones, a firewall. You'll have to decide what you need and select accordingly.

How We Rate Antivirus Software

We evaluate antivirus software on three criteria: ease of installation and use, based on the reviewer's own experience; system impact, based on standardized benchmark tests; and malware detection, for which we use independent lab AV-TEST's periodic and detailed analyses. Malware detection is the most important factor, but we won't recommend a product if it's impossible to use or drastically slows down a computer or Android device.

We spend three to four hours testing and analyzing each piece of Windows antivirus software. For Android, the process takes an hour for each app.

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    Your comment
  • bought the bitdefender one for 25ish pounds.

    Got a non working activation key in return. And i had to delete my free 1 years trail of Kaspersky which worked just fine!
  • Comodo Internet Security seems to work well with little system slowdown compared to most products. Offers FREE antivirus and firewall which beat the Microsoft and most paid programs. Has caught virii & blocked malware that other products would have allowed. I do supplement the anti-malware scans for peace of mind sake, but then I haven't found products with the others that weren't already identified by Comodo.
  • Here is a critical test that I think should be included in every antivirus program test: Impact on TimeMachine. I had Avira installed on my computer - and as a result, a backup of 20GB of data with TimeMachine would take more than three days. I had to uninstall Avira - and now my backup is back to normal.
  • What is "normal"?
  • I think you may want to check out ESET AV.
  • Originally Avira Free didn't bug you to upgrade as I have used it for years. Now it does.
  • No mention of QuickHeal ? or it wasn't tested ? I heard it;s pretty good with excellent Customer Support.
  • Sandboxie was an excellent addition to your internet security but it seems to crash my PC now, have not found a good alternative yet.

    I also use Malwarebytes anti exploit (protection against zero day attacks) and Zemana anti logger to minimise effectiveness of key loggers in case they get through the defence. All of these programs are free.

    I would not pay for AV and find there is no need to pay as long as you have a good backup strategy in place just incase you get something nasty on your PC. Another couple of things that will reduce your chance of infection are:

    1. Install adblock plus on your browser.

    2. Disable javascript on your browser (you can switch it on briefly if there is something on a site you really need to see)

    3. Uninstall Java from your computer, this is known to be the biggest vulnerability that hackers use.

    4. Uninstall adobe reader and flashplayer as they also contain vulnerabilities that hackers use.

    5. Make sure your windows and all other programs are upto date with patches and that you are running the latest version.
  • I still use Norton Internet Security and it works like a charm
  • I will suggest you to go with norton security. this is the best security to use.
  • We uses AVIRA from all our software house outlets its very very good, our employee's are also satisfied ! Thumb(s) Up !!
  • Kaspersky Total Security provides best protection for your Computer. It's good, but the competition is better and cheaper.
  • The only problem I found with Avira is that is made Time Machine an my iMac terribly slow.After removing Avira the backup speed was back to normal again. I hope Avira will tackle this problem soon.
  • I am using Avira Free version. It apparently is regarded as the best, free or paid. HOWEVER, it is almost impossible to set up unless you are an MIT PhD in IT. And maybe not even then. The "scan" takes almost 3 days and slows and almost stops you from working on your PC. There is apparently no choice of scan option although it hints to a "quick" scan but good luck in finding how to set it up for running on a schedule. I allow the scan to run for a day then stop it so I can have the use of my computer back. There is no support for the free version and attempting to use the "forum" or "community" help it very close to useless. I had purchased the paid version a year ago, found it even more complicated than the free version and as a result cancelled it. Now how's this for being ironic: I had Microsoft Windows Defender (free, along with Malwarebytes free) for over a year and experienced NO problems whatsoever. And it was so very easy to use. Go figure. If you go to Avira be ready to deal with the frustrations and aggravation.
    PS: The upshot is I Googled "Top Rated Antivirus Programs" and found this article expounding on Avira. What's a body to do? I think that I will keep my Malwarebytes and go back to Windows Defender as Avira is just so difficult.
  • I am using Comodo Free Antivirus for my Windows PC. It's provides complete virus protection & working perfectly. But here this product is missing. why?
  • Johnrose said:
    I am using Comodo Free Antivirus for my Windows PC. It's provides complete virus protection & working perfectly. But here this product is missing. why?
    Thanks for your reply JohnRose. I have replaced Avira as what good is the best if you can't understand how to use it? AND it takes 3 days to complete a scan stopping the use of your computer during that time? Malwarebytes, Ccleaner and Microsoft Window Defender work easily and just fine. As they say: "KISS". (Keep It Simple, Stupid).
  • I started with Norton in 2006, back when it was a resource hog. Later in 2009 I switched to McAfee for a year, and then back to Norton. I dropped off Norton and used free AVs like Avira and Comodo Internet Security for a while, before switching to Kaspersky in 2013.

    Have been using Kaspersky ever since, and it has never let me down. Plus it is very cheap where I live, I got an Internet Security license 3 years, 3 PCs for $25.
  • Rishabh Tatiraju said:
    I started with Norton in 2006, back when it was a resource hog. Later in 2009 I switched to McAfee for a year, and then back to Norton. I dropped off Norton and used free AVs like Avira and Comodo Internet Security for a while, before switching to Kaspersky in 2013. Have been using Kaspersky ever since, and it has never let me down. Plus it is very cheap where I live, I got an Internet Security license 3 years, 3 PCs for $25.
  • Tks for ur reply Rishabh, as I noted I have given up and dropped Avira in favor of MS Windows Defender with Malwarebytes and Ccleaner. Worked before so why not now? AND it's EZ.