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Ad and tracker blocking that actually works

Block ads and third-party trackers with one good content blocker in the browser, optionally backed by network-wide DNS blocking, and know why the browser you choose now decides how strong the blocker can be.

  • Low threat
  • Time 20 minutes
  • Difficulty Easy
  • Last verified

What this protects, and what it doesn't

Protects

  • Third-party trackers: a wide-spectrum blocker stops most advertising and analytics scripts from loading and following you across sites.
  • Malvertising exposure: blocking ad networks removes a common delivery path for scam and malware ads.
  • Bandwidth and clutter: pages load lighter and with fewer dark-pattern pop-ups and cookie walls.
  • Whole-network coverage (with DNS blocking): devices that cannot run an extension, like smart TVs, get some blocking too.

Does not protect

  • It is not anonymity. Blocking trackers reduces profiling but does not hide your IP or make you anonymous; that is what Tor is for.
  • First-party and in-page tracking slips through DNS-level blocking, because it comes from the same domain as the site.
  • Logged-in tracking continues. If you are signed in to Google, Facebook or similar, they track you through your account regardless of blockers.
  • It is cat-and-mouse. Some sites detect blockers or serve server-side ads; cosmetic hiding needs list updates to keep working.

Prerequisites

  • A desktop or mobile browser that supports extensions, or a network where you can set DNS.

Step by step

  1. Understand why the browser matters now

    Chrome's extension platform changed. The classic full uBlock Origin relies on an API (webRequest) that Chrome's Manifest V3 restricts. Chrome began disabling Manifest V2 extensions in October 2024 and completed the change during 2025, so the full uBlock Origin no longer runs on Chrome. Its Manifest V3 successor, uBO Lite, works within the new limits and is lighter, but it drops some capabilities (no per-site dynamic filtering, filter-list rule caps, no generic cosmetic filtering unless you raise it to "Complete" mode).

    Firefox keeps the full webRequest API, so the full uBlock Origin keeps working there, and Mozilla has said Firefox will keep supporting the blocking webRequest API. That is why the single most effective blocking choice today is "Firefox + full uBlock Origin".

  2. Install one good blocker (not three)

    Pick one wide-spectrum blocker and stop there; stacking several causes conflicts and breakage.

    • Firefox (desktop and Android): install uBlock Origin from addons.mozilla.org. Its default lists (EasyList, EasyPrivacy, and uBO's own) already cover ads and trackers.
    • Chrome / Edge / Chromium: install uBO Lite, and set its filtering to "Complete" for the strongest mode the platform allows.
    • Safari: use a reputable content-blocker app (for example AdGuard for Safari); Safari uses a different blocking mechanism than uBO.

    uBlock Origin is free and open-source. Download it only from the official browser add-on store to avoid look-alike copies.

  3. Trust the defaults, add lists sparingly

    uBlock Origin's out-of-the-box lists are well tuned; you do not need dozens more. If you want a little extra, enable one privacy-focused list (such as an additional tracker list) and keep an eye out for site breakage. Too many overlapping lists slow things down and cause false positives without much benefit.

  4. Optional: block at the network with DNS

    To cover devices that cannot run an extension, add DNS-level blocking for the whole home:

    • Pi-hole or AdGuard Home: self-hosted DNS sinkholes on a small always-on device; they refuse lookups for known ad and tracker domains across every device on the LAN.
    • A filtering resolver: NextDNS or AdGuard DNS do the same without self-hosting (see Encrypted DNS).

    DNS blocking is broad but blunt: it can only allow or block a whole domain, so it cannot hide page elements or block trackers served from the site's own domain. Use it with an in-browser blocker, not instead of one.

  5. Fix the rare broken page

    When a site misbehaves, open the blocker's panel and toggle it off for that site, reload, and confirm that was the cause before leaving it off. In uBlock Origin you can also use the per-site power button rather than disabling the extension globally. For anti-adblock walls, a cosmetic filter list helps, but some sites you will simply have to accept or avoid.

Common mistakes

  • Installing several ad blockers at once; they conflict and break pages without blocking more.
  • Using "AdBlock" or "Adblock Plus" and assuming it blocks everything — their "Acceptable Ads" programme lets some paid ads through by default.
  • Relying on DNS blocking alone and expecting in-page or first-party trackers to disappear.
  • Downloading a blocker from a random website or a look-alike listing instead of the official add-on store.
  • Staying signed in to big platforms and assuming a blocker stops them profiling you.

Going further

A content blocker pairs naturally with browser hardening (see Browser hardening) and with a private default search (see Private search engines). To see what a site can still read about your browser after blocking, use the Browser Fingerprint Inspector, and strip tracking parameters from links you share with the Tracking Link Cleaner.