How to Test Your Ad Blocker (Quick Guide)
Block You TestA practical walkthrough of testing your ad blocker: which layers to check, what a partial result means, and how to fix a blocker that stopped working.
Most people install an ad blocker, see ads disappear, and never think about it again — until ads quietly come back. If you have never run a check before, start here: test your ad blocker first, then read what each result means. The whole check takes under a minute. This guide walks through the three layers a blocker uses and what a test result actually tells you.
The three layers every ad blocker uses
A blocker is not one filter. It is three, and each catches different things:
- Cosmetic filters hide page elements that look like ads — anything carrying class names like
adsboxorad-banner. If these stop matching (a site renames its classes), ads reappear even though the blocker is "on". - URL rules refuse requests whose path looks like advertising, such as anything served from an
/ads/directory. - Network filters block connections to known ad servers before a single byte loads. This is the layer that matters most on YouTube, where ads and videos share domains.
A proper test places one bait in each layer. Run the test on our homepage and you will see three verdicts, one per layer.
Reading a partial result
If two baits are blocked and one sails through, your blocker is partially working. That is usually one of three problems:
- Stale filter lists. Open your blocker's settings and update the lists. EasyList and its variants update daily; a blocker that has not refreshed in months misses new ad patterns.
- Whitelist leftovers. At some point you clicked "allow ads on this site to support the creator" and forgot. Check your blocker's allowed-sites list.
- The site serves ads from its own domain. Some sites bundle ads with normal content specifically to defeat URL rules. Only network filters with hand-written exceptions catch these.
How often should you test?
After every blocker update, after browser updates (extensions sometimes get disabled silently), and any time you see a single ad where you used to see none. One ad getting through usually means the whole cosmetic layer is stale — it rarely stays at just one.
FAQ
Does the test itself contain ads?
No. The baits are instrumentation — a styled div, a local image, a local script. Blocking them is the point; allowing them changes nothing.
Can a site detect that I use a blocker?
Yes — sites can run the same bait logic in reverse and react (nag walls, blocked content). Our test runs entirely in your browser and reports nothing to anyone.