Low-entropy fields
Brands, mobile and platform are read from the exposed API. The brands list can include a deliberately unusual GREASE brand; it is kept as reported and is not treated as another installed browser.
BrowserCheck · Browser environment diagnostics
Client Hints Test
Inspect low-entropy User-Agent Client Hints and request available architecture, bitness, model, platform version and full-version fields.
User-Agent Client Hints provide a structured alternative to reading tokens from a User Agent string. This page tests navigator.userAgentData, reads its low-entropy fields and requests selected high-entropy values. Missing fields are shown explicitly rather than guessed from the User Agent.
Results in this browser
Running local checks…
Copied and printed output omits IP addresses, the full User Agent, exact versions, fingerprint hashes, and precise location.
What is tested and how to read it
Requested high-entropy values
The request asks for architecture, bitness, model, platformVersion, fullVersionList and wow64. A successful call can still omit fields. An empty model is a returned empty string, while an absent field is unavailable.
Partial and blocked responses
Low-entropy values remain visible if the high-entropy request is absent, denied, fails or times out. The page labels the result as available with limitations and explains the high-entropy stage.
JavaScript and HTTP differ
This is a JavaScript API test. It does not configure Accept-CH, capture Sec-CH-UA request headers or verify the hints a different server would receive.
Test limitations
- Support differs across browser engines; an absent API is not a security verdict.
- Privacy settings, policies and browser implementation choices can affect exposed information.
- Structured values are still browser reports. They do not verify the underlying hardware or remove the need for feature detection.
Next steps
- Check the low-entropy fields first, then look at which high-entropy fields were actually returned.
- Compare with the User Agent checker to understand reduced version tokens. Share only the safe status summary unless raw fields are needed.
Frequently asked questions
Why does Firefox or Safari show Unsupported?
The page uses the exposed navigator.userAgentData API. If this engine does not expose it, there is no local Client Hints result to inspect.
Why is the model empty?
The browser may return an empty model, for example for a device category with no model value to report. Empty and absent fields are kept separate.
Are these the headers my server receives?
No. HTTP Client Hints depend on request behavior and server policy. This test only reads the JavaScript API.