How do you choose an antivirus software? How do you know what you choose is the best?  You could ask your tech friends for advice, but their anecdotal reports and personal opinions aren’t definitive facts to help you make an informed decision. Avoid buyer’s remorse. Use these five resources as your guides for choosing your next antivirus.

AV-Comparatives

Based in Austria, AV-Comparatives claims to have the most comprehensive tests available. It conducts tests on various aspects of an antivirus software, including real-world protection, file detection, heuristic analysis, false positives, and performance. Various platforms are supported, including Windows, Mac, Linux, and Android. The findings of the tests are available for free, public viewing and downloadable as PDF files. If you want a more visual presentation of the results, AV-Comparatives offers interactive charts.

In addition, AV-Comparatives gives awards or ratings to various products that excel in their tests. In December 2015, the organization gave an Advanced+ rating to Avast, BitDefender, Kaspersky and five other security vendors for excelling in the real-world protection test it conducted from August to November 2015. It gave the same rating to 11 security products for passing its October 2015 performance test with flying colors.

AV-Test

Another source of comparative tests is available from AV-TEST. Like AV-Comparatives, this independent German organization examines various security software for Windows, Mac OS, and Android. It uses three main criteria for testing every software: protection capability, impact on performance and usability. AV-TEST also conducts test based on repair performance, or how well a security product performs on cleaning up after virus infections.

As of February 2016, AV-TEST lists products from Avira, Kaspersky, Symantec, and Trend Micro as the best security software for Windows 7. In 2015, it named Symantec products the best in protection for both consumer and corporate users.

Dennis Technology Labs

Dennis Technology Labs is based in the UK and uses realistic tests that mirror the user experience. Each test, which involves visiting infected websites and exposing the test computer to the latest threats, is arduous and lasts a couple of months. The laborious process limits the number of security products being tested, so you probably need to find another resource if you want an evaluation of a lesser-known product.

Test results are published on a quarterly basis and available as PDF downloads. In December 2015, Dennis Technology Labs gave its best rating, AAA, to Norton Security, Kaspersky Internet Security, ESET Smart Security 8 and three other products.

ICSA Labs

ICSA Labs (International Computer Security Association) does not make comparisons between security products so much as bestow certifications to them. Its antivirus testing reports, which are published on a monthly basis, only give a pass or fail status for products it assesses. As such, you can use testing reports from ICSA Labs to verify that a given antivirus software at least meets the standards, regardless of how its performance, accuracy, and usability compare to others.

Virus Bulletin

Virus Bulletin is a UK-based magazine that performs its own independent testing. It provides the VB100 certification to products with high detection rates, minimal performance impact, and solid stability while not generating false positives. Tests are conducted on a monthly basis.