Ad Blocker Test: How Many Trackers Does Your Browser Block?
A free ad blocker and tracker blocking test against 36 known ad and analytics trackers — Meta, Google, TikTok, and more. See exactly which ones get through your browser, ad blocker, or VPN.
This test runs entirely in your browser. No tracker data, scores, or results are ever sent to or logged on my server.
Understanding Your Score
The table below shows what each rating means, based on the percentage of trackers blocked above.
| Rating | Trackers Blocked | What It Means |
|---|---|---|
| Well protected | 67–100% | Your browser, extensions, or VPN are stopping most known trackers before they can load. Advertisers get very little to work with. |
| Partially exposed | 34–66% | Some categories of trackers are getting through — commonly analytics or session-recording scripts, which are blocked by fewer default filter lists than social ad pixels. |
| Wide open | 0–33% | Most trackers on this list are loading freely. Your browsing behavior is very likely being logged by multiple ad and analytics networks right now. |
The 36 Trackers Tested
Sorted by category. "Blocked" means the request never reached the tracker's server — "Loaded" means it did, whether or not you have an account with that company.
Testing 36 known trackers…
Why This Matters in the US
Ad tracking runs at a scale in the US that most people underestimate:
- No federal tracking law: Unlike the EU's GDPR, there is no comprehensive US law that limits how many trackers a website can run or requires opt-in consent before they load
- A $200B+ industry: US data brokers and ad-tech companies build detailed profiles from tracking data like this — see the Data Broker Exposure Report for how that data gets bought and sold
- State-by-state opt-out rights only: California (CCPA/CPRA), Virginia (VCDPA), Colorado (CPA), and Texas (TDPSA) give residents opt-out rights over targeted advertising. Some of these states legally require sites to honor Global Privacy Control (GPC) — a browser signal that automatically requests opt-out — but even GPC doesn't stop a tracker's request from loading in your browser the way blocking does; it only tells the site not to sell the data it already collected
Blocking a tracker's request is a stronger, more immediate form of protection than an opt-out request — including automatic ones like GPC: the data is never collected in the first place, regardless of what state you live in or what signal your browser sends.
How This Test Works
When you load this page, your browser requests the real endpoint used by each of the 36 trackers above — using the same method that tracker actually uses on real websites:
- Pixel-style trackers (Snapchat, Pinterest, LinkedIn, DoubleClick, and other ad-tech beacons) are loaded as a real tracking pixel, exactly like they'd appear in a page's HTML
- Script-based trackers (Meta Pixel, Google Tag Manager, Hotjar, Microsoft Clarity, and similar) are requested using the browser's preload mechanism, so the request is correctly classified as a script by ad blockers — without ever running the third-party code on this page
- A handful of trackers (Google Analytics, Mixpanel, Amplitude, Segment) are called the way their own SDKs do it, via a background network request
- Matching each tracker's real-world loading method matters: most ad-block filter lists write rules for a specific request type, so testing everything the same generic way can make a working blocker look far less effective than it actually is
- A request that completes normally — the tracker's real pixel image or script file arrives — is counted as Loaded. A request that fails at the network level (blocked by an extension, a DNS-level blocklist, or built-in browser tracking protection) is counted as Blocked
- A tracker that doesn't answer within a few seconds is tried once more. If it still doesn't answer, it is shown as Inconclusive and left out of your score — a slow tracker server says nothing about your blocker
Limitation: This test measures whether these specific tracker requests are blocked right now — it does not, and cannot, show what trackers have recorded about you on other websites in the past. No browser API exposes that information to any site, including this one. It also can't detect a blocker that quietly substitutes a harmless placeholder response instead of rejecting the request outright — a technique some blockers use to avoid breaking pages — since from the browser's perspective that still looks like a completed request.
How to Block More Trackers
If your score above was lower than you'd like, here's what actually moves the needle:
- Install a filter-list-based extension: uBlock Origin blocks the large majority of trackers on this list out of the box using community-maintained filter lists
- Switch to a privacy-focused browser: Brave and other privacy browsers ship with tracker blocking built in — no extension required
- Use a VPN with a built-in tracker blocker: plain VPNs only hide your IP address, but Proton VPN's NetShield, NordVPN's Threat Protection, and Surfshark's CleanWeb filter known ad and tracker domains at the network level
The Verdict: Blocking Beats Opting Out
Every tracker marked "Blocked" above is a request that never left your browser — no data was collected, logged, or sold. That's a stronger guarantee than any opt-out form.
If your score is low, a filter-list extension like uBlock Origin closes most of the gap immediately, with a VPN that includes built-in tracker blocking as a second layer.
Compare VPNs With Tracker Blocking