Ads are ugly, they make websites look and perform worse, and their weird tricks—like appearing suddenly or autoplaying videos—can be extremely irritating. Ad blockers seek to rein in those problems and make the web a little bit better. We look through some of the best-known names in the ad-blocking business to help you find the right one for your needs.

Why You Should Block Ads

While legitimate ads can be annoying enough, some ads are deceptive or even dangerous. Some take over your screen, claiming to be from law enforcement and demanding you pay a hefty (and spurious) fine. Some online ads pretend to be from antivirus scanners, proclaiming you've been infected and need to download their malware protection solution, which might itself be malicious or simply a way to scare you into buying a subscription you don't need.

Although it’s rare, we've seen cases where legitimate sites and ad networks were hijacked by attackers. The bad guys submit ads carrying malicious code or pointing to malicious sites, which are accepted and displayed on trusted websites. The practice is called malvertising, and it's perhaps the most compelling reason to try and keep web ads out of your life.

Finally, nearly all advertising in this modern age is built on the privacy-eroding practices of surveillance capitalism. Ever wonder why you see the same ads follow you across different sites? How is Instagram able to show you extremely targeted ads? It's because gathering information about you and your activities is big business. Ad blockers not only keep you from seeing some ads, but the best ad blockers also block the trackers and other tools advertisers use to spy on you.

Many modern browsers have tracker blocking built in. Firefox blocks many trackers in its default mode. Other browsers, including Brave, Opera, and Vivaldi, include ad blockers as well.

How We Test Ad Blockers

All our testing was done on a macBook Pro running macOS 11.6.4. We tested each ad blocker in Chrome version 100. We only tested Chrome extensions, as it remains the world's most popular browser. Note, however, that most of the ad blockers we tested are available for multiple browsers.

To evaluate each service, we wanted both an objective measurement and subjective impressions. On the subjective side, we browsed PCMag's homepage and a review page to see which elements were blocked and whether the site functioned as intended. We also considered the design of each ad blocker, giving preference to well-designed, pleasant looking options.

On the objective side, we used each ad blocker's self-reported analytics on the same pages to see how each performed. We also sought out replicable tests for comparison. We settled on Adblock-Tester to compare how each service blocked ad elements and the EFF's Cover Your Tracks, which focuses on web trackers and browser fingerprinting—an insidious practice that uses unique characteristics of your machine to ID you online for targeted advertising. 

How They Stack Up

Our test results are a mixed bag, which indicates that the differences between how these services work is significant. The one that blocks the most ads may not be the one that works in a way makes sense for you.

Adblock-Tester tests against several features, from standard display ads to error reporting and so on. Scores are presented out of 100. Cover Your Tracks is different, and it looks at three criteria: if your browser blocks tracker ads, if your browser blocks invisible trackers, and how unique a fingerprint your browser presents. A unique fingerprint means you're easy to identify to advertisers.

You can see how all the products we tested compare in the chart below:

For its high scores and sheer breadth of customization options, uBlock Origin is the best ad blocker we tested. Ghostery, which also has a standalone privacy suite, deserves a look for its excellent design and strong scores. We're also giving special attention to Privacy Badger, which performed almost as well as other ad blockers but with a unique, privacy-first approach.

How We Test Ad Blockers

All of our testing was conducted on a desktop computer running Windows 11 Pro. We tested each ad blocker's Firefox extension.

To test each extension's ad-blocking functionality, we browse PCMag's homepage and watch YouTube videos to see how many pre-roll, mid-roll, and overlay advertisements we encounter while it runs. During the test, we note the aesthetic choices for each extension and give preference to those with attractive and easy-to-use layouts. We also factor in scores from ad block extension testing websites such as AdBlock Tester and the Electronic Frontier Foundation's browser testing site.

Go Beyond Ad Blockers

Ad blockers are useful tools, but you can do more to secure your privacy and security online. Consider exploring your browsers' built-in privacy features. All of the popular browsers have tracker blocking built in. Other browsers, including Brave, Opera, and Vivaldi, include tracking blockers too. Check out our list of the best privacy-focused web browsers.

A VPN is a worthwhile privacy investment, too. VPNs use encryption to hide your online activity, making it a little more difficult for advertisers to track you online. Remember that account takeovers and malware infections are the biggest threat to your security online. Enable multi-factor authentication wherever you can online to keep bad guys from taking over your accounts. Download antivirus software, and use a password manager to create and store unique and complex passwords or passkeys for each app you use. It's a lot to remember, so check out our cybersecurity checklist for help with a list of periodic tasks to protect you and your family's privacy and online safety.