Ad Tracker Counter
Free browser-based tracking pixel detector. Scans 30 ad networks, analytics beacons, and surveillance pixels — Google Ads, Meta Pixel, TikTok, LinkedIn, and more — in real time. 100% client-side. No data sent. No sign-up required.
What they're actually doing
Six categories of surveillance — what each one collects and who sees it.
Advertising Networks
Build behavioral profiles by following you across every website that loads their script. A single visit to a site with Google Ads tells Google exactly what you read, how long you stayed, and what you clicked. This data feeds auction systems that serve targeted ads minutes later on unrelated sites.
Analytics Trackers
Measure how users behave on a single site — but the data goes to third-party servers. Google Analytics alone runs on 55% of all websites. Hotjar records your mouse movements and keystrokes in real time. Even 'anonymized' analytics can be re-identified when combined with other signals.
Social Pixels
Placed by social platforms on any site that runs their advertising. They track conversions but also confirm your identity — LinkedIn's Insight Tag tells LinkedIn which companies you visit even when you're not on LinkedIn.com. Facebook's pixel fires on over 30% of the entire web.
Ad Exchanges (RTB)
Run the real-time bidding infrastructure that auctions your attention in under 100 milliseconds. As a page loads, your browser silently pings these exchanges — sharing your IP, approximate location, device type, and browsing context before you've finished reading the headline. Hundreds of advertisers bid on showing you their ad during this window.
Measurement & Verification
Measure reach and frequency of ad campaigns on behalf of brands. These companies track you to verify that an ad was seen by a real human (not a bot) and report audience demographics back to advertisers. They operate quietly in the background of news sites, streaming platforms, and retail.
Marketing Automation
Used by B2B companies to identify which businesses visit their site. HubSpot can de-anonymize your company by matching your IP to corporate IP ranges. Intercom and Drift trigger chat popups based on your behavior — and log everything you type, even if you don't send it.
How ad tracking works
What happens in your browser in the first 200ms after you visit any major website.
You visit a website
The browser makes an initial request for the page HTML. Nothing unusual yet.
Scripts load in milliseconds
The page HTML triggers 10–50 additional requests to third-party domains — analytics, ad networks, social pixels — before you've read a single word.
Your browser pings tracker servers
Each script sends a beacon to its home server: your IP, browser fingerprint, page URL, referring site, time spent, and a unique ID cookie stored in your browser.
Your profile is updated and sold
This data is aggregated with your activity on thousands of other sites to build a behavioral profile. Ad exchanges auction access to this profile in real-time bidding auctions that complete in under 100ms.
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Frequently asked questions
What does this ad tracker detector actually test?
TrackerScan attempts to reach the network endpoints (pixel URLs, analytics beacons, ad exchange tags) used by each of the 30 major trackers. If the endpoint responds — even without sending any of your personal data — we mark it 'reachable'. If your ad blocker intercepts the request, we mark it 'blocked'. A reachable endpoint means any site loading that script can track you across the web.
Does using incognito or private mode prevent tracking?
Partially. Incognito mode prevents cookies from persisting after you close the browser, which breaks one tracking mechanism. However, it does not block tracker network requests — ad trackers can still identify you by your IP address, browser fingerprint, and device characteristics. Our tool will detect the same trackers in incognito mode as in a regular window.
What is a tracking pixel and how does it work?
A tracking pixel is a 1x1 transparent image (or a JavaScript file) placed on a webpage. When your browser loads the image, it makes a GET request to the tracker's server — logging your IP, browser, operating system, timestamp, and the page you're on. Facebook's Meta Pixel, Google's conversion tracking, and most analytics tools use this technique. The 'pixel' is invisible — you'd never know it fired.
Why might a tracker show as 'detected' even with an ad blocker installed?
Most ad blockers use filter lists (EasyList, uBlock filters) that are curated by volunteers and updated regularly — but not every tracker endpoint appears on every list. Newer trackers, obscure measurement companies, and some ad exchanges slip through. This is why our scan is valuable: it shows you exactly what your current setup blocks vs. what gets through.
How does Google's tracking network compare to Meta's?
Google operates the largest tracking network on the web — its scripts (Google Analytics, Google Ads, DoubleClick) appear on approximately 75% of the top 1 million websites. Meta Pixel (Facebook) is on roughly 30% of the web. Together, these two companies can reconstruct a detailed browsing history for most internet users. The next largest players — Adobe, Twitter, LinkedIn — reach 10–20% of sites.
What is real-time bidding (RTB) and why does it matter for privacy?
Real-time bidding is an automated auction system where advertisers bid to show you an ad in the milliseconds while a webpage loads. Your browser silently broadcasts a 'bid request' to hundreds of ad exchanges containing your IP, device fingerprint, browser, location (approximate), and browsing context. Dozens of companies receive this data in each auction — even the ones who don't win the bid retain your data. This happens thousands of times per day for the average internet user.
Does this tool send any of my data to ad companies?
No. TrackerScan uses browser-level fetch() calls with mode: 'no-cors' — these are probe requests that only check whether the endpoint responds. No personal identifiers, browser fingerprints, cookies, or behavioral data are included in these requests. The tool is 100% client-side and runs entirely in your browser. No data is stored on any server.
What is the difference between first-party and third-party tracking?
First-party tracking uses cookies or scripts from the website you're actually visiting — Google Analytics on a news site you read counts as first-party to the news site. Third-party tracking is done by external companies (Google, Meta, Xandr) whose scripts are embedded on thousands of other sites. Third-party tracking enables cross-site profiling — it's why you see an ad for shoes on a news site after browsing sneakers on a shoe store.
How can I reduce my tracker exposure?
Install uBlock Origin (free, open-source) with EasyPrivacy and Fanboy's Annoyance supplemental lists enabled. Use Firefox, which has Enhanced Tracking Protection turned on by default. Use a VPN like NordVPN to mask your IP — trackers that get through filter lists will see a VPN IP rather than your real one. Avoid clicking ads; the conversion pixel fires on landing pages even if you immediately leave.
Why are marketing automation tools like HubSpot and Drift included?
HubSpot, Intercom, and Drift are used by B2B companies but operate as trackers. HubSpot can identify which company you work for by matching your corporate IP range against their database — this is called 'IP de-anonymization'. Drift logs chat widget interactions including unfinished messages. These tools are less visible than Google Ads but can be more invasive for business users.