Ad Blocker Test
Find out whether an ad blocker is active in this browser and how much it catches. The test places invisible bait ad elements on the page and tries to reach well-known ad servers and trackers, then shows exactly which checks were blocked.
Last updated:
Running cosmetic and network checks. This takes a few seconds.
Ad servers & ad scripts network blocking
Trackers & analytics privacy lists
Bait ad elements cosmetic filters
Control requests should always load
How to use the Ad Blocker Test
- Open the page: the test starts automatically and takes a few seconds.
- Read the verdict at the top: whether an ad blocker was detected and the share of checks it blocked.
- Check the lists to see which ad servers, trackers and bait elements were blocked or allowed.
- Change your blocker settings (or turn it off for this site) and press Run test again to compare.
- Copy the results if you want to share them or keep a note.
What each part of the test checks
| Check | How it works | Blocked by |
|---|---|---|
| Ad servers & scripts | Requests well-known ad scripts (AdSense, Google Ad Manager, Amazon, Criteo, Outbrain…). A network error means the request was stopped. | Ad blocker extensions, Brave Shields, DNS filters (Pi-hole, NextDNS, AdGuard DNS), some firewalls |
| Trackers & analytics | Requests common analytics and tracking scripts (Google Analytics, Facebook Pixel, Bing UET, Yandex Metrica, Hotjar). | Privacy lists such as EasyPrivacy, tracker blockers, strict browser tracking protection |
| Bait ad elements | Adds invisible page elements named like ad slots and checks after 1.5 s whether they were hidden or removed. | Extensions with cosmetic (element-hiding) filters, such as uBlock Origin, AdGuard or Adblock Plus |
| Control requests | Loads a file from this site and from a public code CDN. | Nothing should block these. If they fail, the result is marked inconclusive. |
Reading your result
- Everything blocked, bait visible: blocking happens before the browser, usually DNS-based (Pi-hole, NextDNS, a router or VPN filter). It stops ad downloads but leaves empty ad spaces on pages.
- Ads and bait blocked, some trackers loaded: a typical ad blocker with default lists. Add a privacy list (for example EasyPrivacy) for broader tracker blocking.
- Only trackers blocked: built-in browser tracking protection (Firefox, Safari, Edge) without a full ad blocker.
- Nothing blocked: no blocker is active on this page, or this site is on its allow list.
Tips if your ad blocker is not working
- Click the extension icon on this page and make sure it is not paused or allow-listed for this site.
- Check that the extension is allowed in private / incognito windows if you use one.
- Update the filter lists from the extension's settings.
- Chrome extensions built on Manifest V3 can have smaller rule sets; a "lite" blocker may miss some checks.
- Disable other blockers that may conflict, then run the test again.
The test only detects blocking in this browser on this device. Apps and other browsers are not affected by an extension installed here, but DNS-level blocking applies to every app on the network or device that uses it.
Frequently asked questions
How does the ad blocker test work?
It runs two kinds of checks. First it adds invisible bait elements with class names and IDs that ad blockers hide, such as an empty AdSense-style unit, and checks whether they were hidden or removed. Then it sends requests to well-known ad and tracking scripts. A blocked request fails with a network error, while an allowed one gets a response. Control requests to non-ad addresses confirm that your connection works.
Why does it say no ad blocker when I have one installed?
Your blocker may be paused or allow-listed for this site, the extension may be disabled in private windows, or it may use filter lists that do not cover these addresses. Some blockers built into browsers only block trackers and not ads. Check the extension's icon for this page, then run the test again.
What is the difference between network and cosmetic blocking?
Network blocking stops requests to ad servers before anything downloads. Cosmetic blocking hides ad containers already on the page using element-hiding rules. Extensions like uBlock Origin and AdGuard do both. DNS blockers such as Pi-hole or NextDNS work only at the network level, so they block requests but leave bait elements visible.
Does this test load ads or track me?
No. The requests are made in no-cors mode without cookies, so their content is never read or executed, and the responses are thrown away. If your blocker lets a request through, that server receives the same kind of request any web page would send. Nothing about your result is stored or uploaded.
Why is a check marked 'timed out'?
The server did not answer within 6 seconds. Some blockers, firewalls and DNS filters make blocked addresses hang instead of failing, so a timeout is counted as blocked but marked as uncertain. A slow network can also cause it; run the test again to confirm.
Can websites detect my ad blocker this way?
Yes. These are the same basic techniques many sites use to show 'please disable your ad blocker' messages. Some blockers include anti-detection rules for specific sites, but on a generic page like this one the checks are visible.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.