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.
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.