The undetectable ad blocker

How websites detect ad blockers

Anti-adblock systems plant ad bait elements and check if they get hidden, launch test requests to ad servers and check if they get blocked, and look for ad-related JavaScript variables. A normal blocker reacts to all this in a way the page can measure.

Once detected, the site can hide content behind a wall, show a pushy message or silently degrade your experience. You blocked the ads, but the site knows, and it reacts.

What makes a blocker undetectable

Being undetectable means passing those probes as if no blocker was present: the bait element seems visible, test requests seem to succeed, expected variables exist. AdOff operates in the page's main execution context and fakes the bait elements, intercepts detection fetches and masks the variables that anti-adblock relies on.

The result: ads get removed at the network and cosmetic level, but the probes come back clean. No wall, no messages.

Test your current setup

You can check if your current ad blocker is detectable with our free, browser-based test, which runs the same probes that anti-adblock scripts use and shows the result in five seconds.

→ Test if your ad blocker is detectable

Frequently asked questions

Can websites tell if I am using an ad blocker?

Usually yes. Most blockers leave measurable traces. A stealth blocker like AdOff fakes those signals so detection scripts see nothing wrong.

How do I make my ad blocker undetectable?

Use a blocker with a dedicated Stealth layer that runs in the page context and masks bait elements, test requests and detection variables. AdOff includes this in Pro and trial plans.

Is an undetectable ad blocker against the rules?

Blocking ads is your choice on your device. AdOff simply blocks ads without leaving the traces that trigger anti-adblock walls.