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User-Agent parser & generator

Paste a User-Agent string to see the browser, engine, OS and device it claims — or copy a current, real UA string for testing.

Parse a string

Browser
Engine
Operating system
Device

Parsed with pattern matching, the same approach server libraries use. A User-Agent is self-reported and trivial to fake, so treat the result as what the client claims, not proof.

Current common User-Agents

Representative strings for testing and QA. Real browsers update their version numbers frequently and are moving toward frozen, less detailed User-Agents plus Client Hints — do not hard-code these anywhere long-lived.

Reading a User-Agent string

A User-Agent is a single header the browser sends with every request, historically packed with backward-compatibility tokens — which is why almost every modern UA still starts with "Mozilla/5.0" and mentions "like Gecko" or "AppleWebKit" regardless of the actual browser. The useful parts are the browser name and version, the rendering engine (Blink, Gecko, WebKit), the operating system and version, and the device tokens that identify a phone or tablet. This tool pulls those out with the same pattern-matching approach server-side libraries use, and flags known crawler and bot signatures.

It is a claim, not an identity

Anyone can set any User-Agent — antidetect browsers, scrapers and testing tools do it routinely, and every browser has a devtools switch for it. So a UA that says "Googlebot" is not proof the request came from Google (check the reverse DNS for that), and blocking by User-Agent alone stops only the laziest bots. Browsers are also freezing the UA string and shifting detail to User-Agent Client Hints, so parsing will return less over time. Use this for QA, log analysis and understanding what a client reports — not as a security control.

Frequently asked questions

What is in a User-Agent string?
The browser name and version, the rendering engine, the operating system and version, and device tokens for phones and tablets — wrapped in legacy compatibility tokens like "Mozilla/5.0" and "like Gecko" that nearly every browser still sends.
Can I trust what a User-Agent says?
No. It is set by the client and any value can be sent. Antidetect browsers, scrapers and devtools change it routinely. Treat the parse result as what the client claims, and verify anything important another way — for a claimed crawler, check the reverse DNS of the IP.
Why do all User-Agents start with "Mozilla/5.0"?
Historical browser-sniffing. In the 1990s sites served better pages to "Mozilla", so every competitor added it to be treated the same. The token stuck and is now meaningless — every modern browser sends it.
How does the tool decide something is a bot?
It matches the string against known crawler and automation signatures — Googlebot, Bingbot, the AI crawlers, headless Chrome, common HTTP client libraries. A bot that copies a real browser UA exactly will not be flagged; a self-identifying one will.
What are User-Agent Client Hints?
A newer mechanism where the browser sends a minimal UA string and exposes detailed data (full version, platform, model) only on request, via headers or a JavaScript API. Chromium browsers are moving to it, so UA-string parsing returns less detail over time.
Should I block traffic by User-Agent?
Only as a coarse first filter. It stops naive scripts that keep a default library UA, but anything determined just sends a browser string. Combine it with rate limits, behavioural signals and IP reputation for real bot management.
Are the generated User-Agents real and current?
They are representative strings for recent browser versions, for use in testing and QA. Browsers bump their version numbers every few weeks, so do not hard-code these into long-lived code — read the live navigator.userAgent instead.
Does the string I paste get sent anywhere?
No. Parsing runs entirely in your browser against local patterns; nothing is transmitted or stored.

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