Ads and spyware
There’s a saying: “If you aren’t paying for the product, you are the product.” In other words, if a company isn’t selling you something, they’re making their money by selling your attention through ad placements or, worse, selling your data to third-party companies. While this isn’t true 100% of the time — some companies offer a free version with limited features and a premium version as an upgrade — it is true for certain free antivirus options.
We’ve done extensive research to ensure that none of the free antivirus tools we recommend include ads or spyware. You can further protect yourself by learning the red flags to look for when downloading apps.
User-friendly privacy policies
Your antivirus — and any connected security tools — may need access to information about you and your devices to function properly, so you need to make sure the company you choose can be trusted with that information. It should have comprehensive, reader-friendly privacy policies detailing what data it collects and how that data is used, ideally including provisions for pseudo-anonymization so data can’t easily be linked to you.
Your antivirus company’s privacy policies should also explain what third parties — such as other companies and organizations like governments or law enforcement agencies — they’ll share your data with, when that data will be shared and what purposes it will be shared for. Most antivirus companies don’t provide full lists of the specific companies that information is shared with, but you should at least be able to see the types of companies (like email marketing services and payment processors).
Additionally, you’ll want to know the company hasn’t been selling user data or participating in other unscrupulous activity. While it’s often impossible to be 100% certain of this, it is easy to find information about companies that have been caught by authorities, so you can avoid them.
Notably, many companies let you opt out of certain types of data collection and any company that sells to Californians must allow you to request deletion of your data. The company’s privacy policy should clarify your ability to do these things so you understand your rights and how to exercise them.
Features
The best free antivirus tools offer both real-time protection and on-demand malware scans, with the option to easily schedule scans. You may get additional features like firewall protection, device optimization tools and safe browsing tools. All of the tools should be intuitive, allowing you to navigate them regardless of your previous tech experience.
Free vs. paid antivirus software
For most people, there’s no need to pay for antivirus software. The free antivirus software built into your computer can protect you from most threats, while third-party free options offer some additional features, like easy scan scheduling. Moreover, the best free antivirus tools often use the same antivirus engines as their paid counterparts, ensuring high-quality malware protection.
However, paid antivirus software often comes bundled with other cybersecurity tools that can be beneficial for some people. Things like advanced device optimization, VPNs, password managers, dark web monitoring, data removal tools and even identity theft protection are often found in cybersecurity suites from top-ranking antivirus companies.
While you can bundle cybersecurity tools, you’ll want to consider whether a comprehensive security and privacy package or the à la carte route is a better option. Note that the one service we always recommend buying separately is a VPN, as the VPNs offered by antivirus-first companies typically lack advanced privacy features and also significantly slowed down my internet during testing.
System resource use
Antivirus software is constantly working in the background to protect you from malware. It should do so without interfering with your daily activities. The best free antivirus tools used less than 5% — often less than 1% — during everyday operation in my tests. Active scans always use more resources, but I generally don’t recommend tools that went above 40% CPU usage during my tests, especially if those scans also took more than 10 minutes. This is doubly true if you’re using an older or under-resourced machine, which will likely experience higher CPU usage.
Issues with Avast
There was a time when Avast was the second thing I downloaded on every new computer (right after Firefox). It was the gold standard of antivirus protection, consistently earning top marks in antivirus testing from third-party labs. Unfortunately, charges were made that Avast sold customer data to over 100 third parties between 2014 and 2020, resulting in a $16.5 million fine from the FTC in 2024.
These sales were conducted through a subsidiary called Jumpshot, which was closed after a statement from then-CEO Ondřej Vlček. Moreover, Gen Digital — a company that owns other top antivirus companies like AVG and Norton — bought Avast in 2021, after the time when the FTC claimed the data was sold. These changes lead us to believe that Avast has likely stopped selling customer data. However, we haven’t re-tested Avast, so we’re unable to recommend it at this time.
Issues with Kaspersky
Kaspersky is a Moscow-based company with antivirus packages for both businesses and consumers. This antivirus has historically performed well in tests from third-party labs, but it was federally banned in the US in 2024, making it illegal for Kaspersky to sell to US customers. Gina Raimondo, the Secretary of Commerce at the time of the ban, stated that the ban was because “Russia has shown time and again they have the capability and intent to exploit Russian companies, like Kaspersky Lab, to collect and weaponize sensitive US information.”
Kaspersky responded to this ban with a statement insisting that it “does not engage in activities which threaten US national security and, in fact, has made significant contributions with its reporting and protection from a variety of threat actors that targeted US interests and allies.” However, Kaspersky remains banned in the US as of writing this article, so we haven’t tested it and therefore cannot recommend it.
