Free tool
Tracker Scanner: See What a Website Loads Behind the Content
Enter any address to see the advertising networks, analytics platforms, session recorders and fingerprinting scripts a page loads, grouped by which company receives the data.
Why your browser cannot do this itself
A web page is forbidden from reading the contents of another site. That rule, the same-origin policy, is the reason a malicious page cannot read your webmail in another tab, and it applies equally to a legitimate tool like this one. So the scan runs on our server, which fetches the page the way any browser would and reports what it finds.
What the categories mean
| Category | What it does |
|---|---|
| Advertising | Selects, delivers and bills for the ads on the page |
| Analytics | Records which pages you visit and what you click |
| Session replay | Records mouse movement and scrolling, then replays your visit for the site owner |
| Data broker | Buys and sells audience data, linking your activity across unrelated sites |
| Fingerprinting | Identifies your browser by configuration, so you can be tracked without cookies |
| Tag manager | A loader that injects other trackers, often dozens of them |
| Consent | The cookie banner itself, which records your choice |
A tag manager deserves particular attention. It is a single entry in the results, but its whole purpose is to load further scripts chosen in a dashboard rather than written into the page. One tag manager can mean five trackers or fifty, and the page's own HTML gives no way to tell.
The limitation, stated plainly
This scan sees the HTML the server sends. It does not execute JavaScript, so it cannot enumerate trackers that are injected after the page loads. Every tool that claims a complete count either runs a full headless browser for each scan or is overstating what it knows.
In practice the shortfall is smaller than it sounds, because most tracking is either declared in the initial HTML or loaded through a tag manager that the scan does detect. Treat the number as a reliable floor rather than an exact total.
What to do about what you find
If you own the site, each entry is a decision you or a predecessor made, and most sites carry several nobody remembers adding. Session replay tools in particular record far more than teams expect, and they are the most common source of accidental sensitive-data collection.
If you are just visiting, a tracker blocker cancels these requests before they are sent. You can confirm that yourself: run the ad blocker test to see what your current setup stops, or the cookie banner check to see whether a site's consent prompt actually gates any of it.
Frequently asked questions
How do I check what trackers a website uses?
Enter the address above. The scanner requests the page from our server, reads the HTML it returns, and matches every third-party host against a public database of known advertising, analytics and fingerprinting services.
Why does the scan find fewer trackers than my browser extension reports?
Because this reads the HTML the server sends, not the page after JavaScript has run. A tag manager can inject dozens of additional trackers at runtime. Those appear here as the tag manager itself rather than as individual entries, so the real count is usually higher than the number shown.
What counts as a tracker?
Any third-party host whose purpose is to observe, identify or monetise the visitor rather than to deliver the content. That includes ad exchanges, analytics platforms, session replay tools, data brokers and fingerprinting vendors. Content delivery networks serving images or fonts are not counted.
Is it legal to scan someone else’s website?
This makes a single ordinary request for a public page, which is what every browser and search engine crawler does. It does not log in, submit forms, bypass access controls or crawl beyond the one page you name.
Where does the tracker list come from?
From a signature database we publish openly under CC0. You can read it, correct it, or use it in your own project without asking.