The Blocker To Get

uBlock Origin is the one ad and tracker blocker worth installing first. It is open-source, light on memory, and kills tracking scripts before they ever run.

Privacy Badger, built by the digital-rights group EFF, now blocks trackers by default using an EFF-generated list rather than learning from your browsing on a fresh install. Local learning still exists as an opt-in mode, but it has been off by default since 2020 because it could make users more fingerprintable.