ad blocker

US /ˈæd ˌblɑːk.ər/
UK /ˈæd ˌblɑːk.ər/
"ad blocker" picture
1.

a piece of software that prevents advertisements from being displayed on a web page or in an application

:
I installed an ad blocker to stop annoying pop-ups.
Many websites detect if you are using an ad blocker.