// traffic audit

tattletell

Your browser has a big mouth. Tattletell hears everything: what a site can read about you, what it actually sends, and which companies end up with it. It all runs in this page, nothing is uploaded. For a full readout of what your browser reveals, see whoami.

Record a visit in your browser’s developer tools, save it as a HAR file, and drop it here. Tattletell searches every request for the values below, in plain text and in the disguises trackers use: URL-encoding, Base64, hex and hashes. The file is read in this page and goes nowhere else.

How to save a HAR file
  • Safari: turn on the Develop menu in Settings ▸ Advanced, then Develop ▸ Show Web Inspector ▸ Network. Reload the page, then use Export.
  • Firefox: open Developer Tools ▸ Network, reload, click the gear icon and choose Save All As HAR.
  • Chrome and Edge: open DevTools ▸ Network, reload, then use the download arrow to export. Recent versions drop cookies unless you pick the option that includes sensitive data. Menu wording varies by version.
  • Use a fresh private window so extensions and logins don’t colour the result. Delete the HAR afterwards; it can contain your session cookies.
Drop a .har file here, or
Paste HAR text instead

what this can and can’t tell you

  • It finds values it was told to look for. Salted hashes, encryption, compressed or binary payloads are invisible to it, so a clean result doesn’t prove nothing was sent.
  • A HAR holds what the browser reported. Headers the browser adds late, and anything the server works out itself (your IP address, TLS and HTTP fingerprints), may not appear.
  • Short values such as “8 cores” only count when sent under a matching name like hardwareConcurrency, and are marked “likely”.
  • Company and category labels come from the DuckDuckGo Tracker Radar list (CC BY-NC-SA 4.0), trimmed to about 1,900 widely seen domains. A host missing from it is shown as unlisted, which is not the same as harmless. Cookie links marked “likely” are guessed from the cookie’s name.
  • This page can’t see your host name, serial number or network addresses. The Tattletell Mac app can, and also loads sites itself.