Which anti-virus software should you be using? It's a question that's frequently asked, yet is almost impossible question to answer – how do you judge which is the "best"?

The problem is that there are so many variables; what should you be basing your decision off? Scan speed? System resource usage? Malware detection rates? Update frequency? There's no right answer… At least if you have access to some up-to-date independent tests and reviews you'll be able to make a more informed decision.

Here we take a look at five of the best online resources for checking anti-virus performance.

Virus Bulletin

At its core, Virus Bulletin is a magazine that covers the prevention, detection, and removal of malware and spam. Aside from its extensive and in-depth blog, the publication also regularly tests anti-virus and anti-spam products.

virus-bulletin

For their anti-virus testing, they measure detection rates using their "RAP" (Reactive and Proactive) methodology. It uses the newest samples from the time the products were submitted for testing, and then adds samples that were discovered after the submission date. The theory is that using this approach allows them to measure both a product's ability to handle emerging malware and its ability to measure previously unknown malware.

Any product which can a) detect 100 percent of "in the wild" malware samples listed, and b) generate no false positives when scanning a set of clean samples, will be given the coveted VB100 certification. The logo for the award will be displayed alongside the product on their results page.

AV-TEST

AV-TEST has been a leading name in the field of anti-virus testing for more than 15 years. The organization is based out of Magdeburg in Germany and is entirely independent.

They run tests across four key application areas; Android, Windows, Mac, and business users. The tests are run every four months on average and the results all displayed for free on their website.

av-test

Unlike Virus Bulletin, which uses a quadrant graph to display their RAP Test findings, AV-TEST use a simple rank-able list. The three testing measures they use are "Protection, "Performance", and "Usability", and each section is given 0-5 stars.

You can also enter the results of each individual anti-virus suite to discover how the score was achieved; the three sections are broken down into specific areas such as zero-day malware attacks, false positives, and real-world performance.

In addition to their regular testing, they also have annual awards. They issue ten awards per-year, with a consumer winner and a corporate winner for each category. The current holder of the protection award is Trend Micro, while the current holder of the performance award is Kaspersky Lab.

AV-Comparatives

Like AV-Test, AV-Comparatives is an entirely independent organization that's dedicated to testing anti-virus products on Windows machines, Macs, and mobile devices. On their website they claim that

"[our] Real-World Protection Test is the most comprehensive and complex test available when it comes to evaluating the real-life protection capabilities of anti-virus software".

The site offers far more tests than its competitors; there are nine available to choose from, and they include "File Detection Tests", "Heuristic / Behavior Tests", and "Anti-Phishing Tests".

av-comparitives

For each section they run one test every quarter, and the results are available via a PDF download. If you don't want to go trawling through PDFs just to find the information you need, they also offer an interactive chart directly on their website. You can organize the data by test-type, date, and vendor – thus giving you a direct snapshot of the anti-virus market at any given moment.

Finally, they also offer comprehensive reviews that are also available for download on PDF. These reviews cover subjects such as firewalls, parental controls, and Linux protection.

ISCA Labs

ISCA stands for "International Computer Security Association". It's a US government-authorized institution that has grown to become America's main anti-virus product testing public body since its launch in 1989.

They conduct tests in the fields of anti-virus, anti-spyware, mobile apps, networking, and web apps.

isca-labs

Their anti-virus testing is scored against a matrix. It takes into consideration on-demand and on-access testing, which both include testing for wild infections, common infections, and wild non-infections. Tests are conducted across desktops/servers, gateways, groupware, and managed services.

The main results page is less user-friendly than the previous three options. There is no grading/ranking and no sortable results. Instead, the results just display the signature number of the product tested, the operating system it was tested on, the date it was tested, and a simple pass or fail outcome.

Dennis Technology Labs

Dennis Technology Labs is probably the least well-known site on this list, but it's well-worth a look. They are an independent testing facility that evaluate all aspects of personal and business technology – but their specialty is security software.

dennis-lab

They conduct their tests using their own methodology. The site doesn't go into detail about what the testing involves, but it does say that their "purpose-built lab is capable of exposing multiple security products to a wide range of threats that exist in the real world at the time of testing", adding "results are truly representative of how different products respond to adversaries".

Like other sites on this list, they conduct tests on quarterly basis. Each results package is available for download and is broken down into "Total Accuracy Ratings", "Protection Ratings", "Protection Scores", "Protection Details", and "Legitimate Software Ratings". Each section has a range of charts, lists, scores, and data to accompany it, as well as revealing some of the methodology behind each test.

What Is Your Favorite Anti-Virus Site?

Which site do you turn to when you're looking to find out information about the various anti-virus products on the market?

Have we missed a little-known laboratory that should have made the list? Perhaps that an aspect of the methodologies of the ones we mentioned that you don't agree with?

We'd love to hear your thoughts. You can let us know what you think in the comments section below.