Free User Agent Parser — Decode Any UA String
Every HTTP request carries a User-Agent fingerprint. Paste one here (or parse your own with one click) and the tool identifies browser and version, rendering engine, operating system, device class and whether the string belongs to a bot or AI crawler like GPTBot or Google-Extended.
🔒 100% Private — runs in your browser, nothing is uploaded使い方 This User Agent Parser （ステップごと）
- See your own UA — It is pre-filled in the top box — click Parse My UA.
- Paste any UA string — From server logs, analytics or DevTools network tab.
- Read the breakdown — Browser, engine, OS, device and bot status appear instantly.
The Accidental Fingerprint — Under the Hood
User-Agent strings date back to 1993 and became a de-facto fingerprinting vector: browser, version, engine and OS combine into a string that narrows users to a small crowd. Modern browsers now ship reduced, frozen UA strings (Chrome 110+ "major version only", Safari's fixed pattern) precisely to slow fingerprinting down — which is why parsing them is getting harder.
Frequently Asked Questions
Why does my UA say HeadlessChrome?
Automation tools and some privacy browsers spoof or trim the UA string.
Is my UA private?
It is read locally and never sent anywhere by this page.
Can UAs lie?
Constantly — UA sniffing is heuristic; use feature detection for code.
Related Free Tools
クイック概要
User Agent Parser — 100% Free, No Signup is a practical NexVaani tool for completing this task quickly in your browser. Decode any User-Agent string into browser, engine, OS and device type — and see your own instantly. Use the tool, review the result, and continue with a related NexVaani tool when your workflow needs another step.