How we test the best antivirus software
Our reviews were based on an antivirus product's interface, performance, protection, price and extra features. Was the interface intuitive and user-friendly? How badly did malware scans slow performance? How well did the program detect and remove malware? Does the program have any useful additional tools?
Most of our tests were performed on the same Asus X555LA laptop running 64-bit Windows 8.1 (later upgraded to Windows 10), with an Intel Core i3-4005U processor, 6GB of RAM and a 500GB hard drive containing 36GB of files.
Some of our newer performance tests were done on a Lenovo ThinkPad T470 with a 2.5GHz Core i5-7200U processor, 8GB of RAM and 256GB of solid-state storage containing 43.3GB of files.
To assess a program's impact on system speed on both Windows and macOS, we used our own custom tests, which measure how long a CPU takes to match 20,000 names and addresses on an OpenOffice or Excel spreadsheet. The longer it took the laptop to finish either test, the heavier the performance impact.
For malware-detection scores, we use the results of three independent testing labs: AV-TEST in Germany, AV-Comparatives in Austria and SE Labs in England. Each lab subjects the major antivirus brands' products to stress tests involving thousands of pieces of malware, including hundreds of previously unseen samples.