v145 · Privacy · Entropy Budget

UA fingerprint entropy budget

Add or remove UA-Client-Hints fields against a 16-bit fingerprint budget. The meter shows how close your hint set comes to identifying a single device — the whole point of Chrome 145's reduction is reducing this number for the typical site.

budget

Live navigator.userAgent:

Estimated entropy in reduced UA: — bits

Total claimed entropy: — bits

Above ~32 bits you've effectively identified the device. Sites that grew their UA hint dependencies should audit which they really need.

code

// Request high-entropy hints only when you actually need them.
const hints = await navigator.userAgentData.getHighEntropyValues([
  'platformVersion',  // 6-12 bits
  'architecture',     // 2-3 bits
  'model',            // 0-15 bits
  'bitness',          // 1 bit
  'fullVersionList',  // 8-20 bits
]);
// Sum the claimed entropy. Stay under a privacy budget.

see also