Why Use This Tool?
Every browser announces itself with a user agent string — a dense, historical mess that decides which CSS and JavaScript a site serves. This parser decodes any UA string into browser, operating system, rendering engine, and device type; the generator produces a random realistic one for testing.
Your own browser's UA is pre-filled when the page loads, so you can see exactly what your machine announces to every website you visit.
How It Works
- Paste a UA string, or use the pre-filled one from your own browser.
- Click parse to see browser, OS, engine, and device type.
- Or click random user agent to grab a realistic string for testing.
Frequently Asked Questions
How do I parse a user agent string?
Paste any UA string and click parse — the browser, operating system, rendering engine, and device type are detected from the string's structure.
Why do user agent strings look so weird?
History. Browsers pretend to be each other for compatibility — Chrome claims to be Safari 'like Gecko', Edge claims to be Chrome. The parser follows the same precedence rules the industry uses.
What is a random user agent for?
Testing how your site responds to different browsers and devices without owning them — QA teams use realistic UA strings to exercise detection logic.
Tips & Things to Watch
- Blink vs WebKit matters: Chrome/Edge are Blink, Safari is WebKit — CSS behaves differently.
- Mobile detection is part of the parse — the device type line says Yes or Desktop.
- UA strings are self-reported and trivially spoofed — treat them as a hint, not proof.