/tools/user-agent parses a User-Agent header and returns the structured pieces: browser + version, layout engine (Blink, Gecko, WebKit), OS + version, device class (desktop, mobile, tablet) and a bot flag for the common crawlers (Googlebot, Bingbot, AhrefsBot, etc.).
Opens pre-filled with navigator.userAgent so you can immediately see what your own browser advertises. One-click sample buttons cover modern Chrome, Safari iOS, Firefox, and Googlebot for quick reference.
Useful when debugging analytics misclassification, writing a User-Agent allowlist for a CDN rule, or sanity-checking what a server log line actually came from. Pure regex, no network call.