Contact

Reporting a value that looks wrong

This is the message we most want to receive, and the one that is easiest to send badly. Browser behaviour in this area varies far more by platform and version than any documentation admits, so a report we cannot reproduce is still useful: it usually means a page needs a caveat rather than a new number.

Four things make a report actionable:

1. Which page. The URL, so we are looking at the same claim you are.
2. What the page said, and what you expected. The actual figure or text, not a paraphrase.
3. Which browser and version.Your browser's own About screen is the authoritative answer here, and it cannot be spoofed by a website the way the reported version can.
4. Anything unusual about your setup. A privacy extension, a hardened browser profile, a virtual machine or a remote desktop all change what these APIs return, and knowing that saves both of us a round trip.

What happens next: reports we can verify against a specification or vendor documentation are corrected, and the correction is listed on the changelog with its date rather than folded quietly into other work. Reports we cannot reproduce usually end up as an added qualification on the page. We do not promise a response time, because promising one we cannot keep would be worse than promising nothing.

What to get in touch about

• Corrections. If a detected value looks wrong or an explanation is out of date, tell us which page and what you saw.
• The API and widget. Questions about using the free API or the embeddable badge in your own project.
• Privacy questions. Anything about how the site handles data, including how any ads or analytics work. The short version is that detection runs in your browser; the long version is in the privacy policy.
• Partnerships and coverage. If you write about privacy or developer tools and want details or a quote, we are happy to help.

Reporting a security concern

If you believe you have found a security issue with the site, please use the form above with the details and steps to reproduce. We appreciate responsible disclosure and will respond promptly.