Open any site and the panel beside it lists the other companies the page tells about your visit, the cookies it leaves, what it stores on your computer and which scripts read your device's fingerprint. The browsing session is wiped when you close it.
14 of 14
Addresses a test tracker was asked for that showed up in the panel, checked against the server's own log
73,827
Junk events a hostile test page made to hide behind, every one counted as left out while its tracker was still seen
28 checks
In the end-to-end self-test, run with each installer before it is published
Apache 2.0
License for all of the code
From Watchkeeper's self-test on Linux (WebKitGTK 2.52.6), which also runs on Windows and macOS before every release. The test logs are on GitHub.
case studies
Sites change their trackers all the time, and nobody tells their readers. A new ad deal, a new plug-in or a theme update can add a company to every page overnight. The …
case studies
Picture the owner of a small clothing shop. She added a cookie banner because her web designer said the law needed one, and she assumes nothing goes out until a visitor …
use examples
The best time to find out what a page sends is before it’s live. Watchkeeper opens a local copy as easily as a public site, so a developer can check a build on …
testing
A tool that says “this page contacted five sites” is only worth something if the page really contacted five sites. Watchkeeper’s main promise is that …
explainers
A web page isn’t one thing from one place. The article comes from the news site, but the fonts may come from a font service, the ads from an ad network, the share …
case studies
Say a small software company paid an agency to build its sign-up page, and a customer asks a question nobody in the company can answer: which companies does your sign-up …
use examples
Reading back a canvas is the classic first step of a device fingerprint. It’s also how a page turns a chart into an image you can download. So a canvas read on its …
releases
Open a news article and you see a headline, some text and an ad or two. You don’t see the other companies the page told about your visit while it loaded. On many …
the name
On a ship, someone is always on watch. While the rest of the crew sleeps, eats or works below, one officer stays on the bridge, keeps a lookout and notes what passes. …
If a site shows something odd in the panel, or you'd like Watchkeeper to look for something it doesn't yet, write in.