How this ad blocker test works
Ad blockers work in two ways, and the test checks both. Some rules hide parts of a page that look like ads; the five fake ads above use class names that the two biggest filter lists, EasyList and AdGuard Base, both hide. Other rules stop the browser from contacting ad and tracking servers at all; the 30 requests test those.
Every server in the test is on AdGuard's filter lists, which Mistero Adblock uses, and most are on EasyList or EasyPrivacy too, so a mainstream blocker with its lists turned on should stop most of them. They are split into three groups:
- Ads (12): Google AdSense and Ad Manager, Amazon, Taboola, Outbrain, Criteo and other ad networks that place the ads you see.
- Analytics (10): Google Analytics, Hotjar, Mixpanel, Microsoft Clarity and other tools that record what you do on a site.
- Social trackers (8): TikTok, Pinterest, Snapchat, Reddit, LinkedIn and X pixels that report your visit back to those networks.
Is my ad blocker working? Reading your score
Look at the Ads group first. If most of the 12 are blocked, your ad blocker is on and working. Analytics and social trackers often score lower, because many blockers keep tracker lists behind a separate switch. Some also let certain ads through by default under an "acceptable ads" setting, so a partial score can mean the blocker is working exactly as it's set up.
No blocker stops everything, and this is a sample of 30 common servers, not the whole web. A server that is down, or that your network or a VPN with ad blocking already stops, also shows as blocked, because the page can't tell the difference.
Some blockers don't stop an ad script outright: they quietly swap it for a harmless stand-in. The test shows those as "Replaced" and counts them as blocked, because the real ad code never loads.
Why ads still show on your iPhone
- The blocker is off in Settings. Installing the app isn't enough. Go to Settings › Apps › Safari › Extensions and turn the blocker on. On iOS 17 and earlier it's Settings › Safari › Extensions.
- You're not in Safari. Content blockers from the App Store work in Safari, not in Chrome, Firefox or other browsers on iPhone.
- The filter lists haven't downloaded. Open the blocker's app once while you're online so it can fetch its lists.
- The ads are inside an app. Games, free apps and the YouTube app show their own ads, and Safari settings don't reach them.
Pop-ups are a separate problem with their own fixes: see how to stop pop-up ads on iPhone.
What happens when you run the test
The fake ads are checked as soon as the page loads, without contacting anyone. The server check starts only when you press Start. It asks each server for one file, without cookies, and only looks at whether the request went through; the file itself is never run. Requests your blocker lets through reach those companies, the same as on any site with ads. The result stays in your browser.
Questions
Is my ad blocker working?
Press Start above. If most of the 12 ad servers show as blocked and the five fake ads are hidden, it is working. A low score usually means the blocker is turned off in Settings, or you are testing in a browser it doesn't support.
Why are ads blocked but trackers aren't?
Many blockers keep tracker lists in a separate switch that starts off. In Mistero Adblock it is called Tracker Blocking. Turn it on, reload this page and run the test again.
Does this test work in Chrome on iPhone?
It runs, but ad blockers from the App Store only work in Safari on iPhone and iPad, so Chrome will usually score close to zero. Open this page in Safari to test your content blocker.
Does the test check ads in apps, games or YouTube?
No. It only measures what blocks ads in the browser you open it in. Ads inside apps and games, including the YouTube app, are outside Safari's reach.
Is it safe to run?
Yes. The page doesn't run any ad code. It asks each server for one file without cookies and only checks whether the request went through. Your result isn't stored or sent to us.