Free tool
YouTube Ad Block Test
Tests the specific hosts YouTube uses to deliver advertising, and explains the part of YouTube's ad pipeline that no domain blocker can reach.
0 of 3 YouTube ad delivery hosts were stopped. A good score here does not guarantee an ad-free YouTube, for the reason explained below.
Why YouTube is harder than the rest of the web
On a normal website, an advertisement is a separate request to a separate domain. Cancel the request and the ad never arrives. That model is what makes ad blocking work, and it is why our general ad blocker test is a meaningful measurement.
YouTube does not work that way any more. A growing share of its advertising is inserted server-side, meaning the ad is spliced into the same video stream that carries the content you asked for, delivered from the same host, over the same connection, with the same URL pattern. From the browser's point of view there is nothing separate to cancel.
What this test can and cannot see
The hosts in the first group are genuinely separate ad infrastructure, and blocking them stops a real portion of YouTube's advertising, particularly the display units around the player and some pre-roll paths. Those are worth testing and the result is meaningful.
The second group is listed but marked not testable. These are paths rather than hosts, sitting under domains that also serve legitimate traffic. Probing them from a browser would either produce a meaningless result or require breaking playback. Rather than test them badly, we list them so the picture is complete.
What actually helps
Because the ad and the content arrive together, blocking YouTube ads has shifted from filtering requests to detecting and skipping the inserted segments client-side. That requires the blocker to understand the player's own state, and it requires updating whenever YouTube changes that state. Filter list freshness matters far more here than filter list size.
If ads are appearing despite a good score above, the fix is almost never a new blocker; it is usually a stale list or a cached player script. Our YouTube ads not blocking guide walks through the order to check things, and this longer write-up covers why the breakage recurs.
Related tests
Run the full ad blocker test to see how your setup handles the rest of the web, or the DNS blocking test if you want to know whether your network is filtering before your browser even sees the request.
Frequently asked questions
Why do I still get YouTube ads when this test says blocked?
Because YouTube increasingly serves ads through server-side ad insertion, which stitches the advertisement into the same video stream as the content. There is no separate ad request to block, so domain-level filtering cannot stop it. A perfect score on this test and an unskippable ad on YouTube are entirely consistent.
Which domains does YouTube use for ads?
The blockable ones are doubleclick.net, googlesyndication.com and googleadservices.com. The rest of the ad pipeline runs through paths under youtube.com and googlevideo.com that also carry legitimate video data, which is why blockers cannot simply filter those hosts.
Can I block googlevideo.com to stop YouTube ads?
No. googlevideo.com delivers the actual video content as well as inserted advertising. Blocking it stops YouTube working entirely. This is the core difficulty with YouTube ad blocking and the reason it requires constant filter maintenance rather than a single rule.
Why does my ad blocker keep breaking on YouTube?
YouTube ships anti-adblock changes frequently, often several times a month. Each change alters how ads are requested or detected, and filter lists have to be updated in response. A blocker with slow list updates will break repeatedly; one with daily updates recovers within hours.