FreeToolsWorld

User Agent Parser

Break a user agent string into browser, engine, OS and device.

Developer Tools Free, no sign-up Runs in your browser

Your own browser's string is loaded for you. Replace it with any other to parse that instead.

—
Browser
—
Engine
—
Operating system
—
Device type

Breakdown

Client hints from your browser

About the User Agent Parser

User Agent Parser takes the long, historically confused string a browser sends with every request and tells you what it actually describes: the browser and version, the rendering engine, the operating system, and whether the device is a desktop, a phone, a tablet or a bot.

User agent strings are famously misleading. Nearly every browser still claims to be Mozilla for compatibility reasons dating back to the 1990s, Chrome strings mention Safari, and Edge mentions both. The parser works through those layers in the right order so that a Chrome string is identified as Chrome rather than as the three other browsers it name-checks.

Your own browser's string is shown at the top, alongside the modern client hints your browser exposes where it supports them. Those hints are the replacement for user agent sniffing, and they are more reliable precisely because they are structured rather than being a sentence.

How to use the User Agent Parser

  1. See your own stringIt is parsed automatically when the page loads.
  2. Or paste anotherFrom a log file, an analytics export or a bug report.
  3. Read the breakdownBrowser, engine, operating system, device type and bot detection.
  4. Copy what you needEach field can be copied individually.

Features

  • Browser name and version
  • Rendering engine and version
  • Operating system and version
  • Device type, including mobile, tablet and bot
  • Your own browser's string shown automatically
  • Client hints displayed where the browser exposes them
  • Handles the common bot and crawler strings

Who uses this tool

The user agent parser is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

  • Investigating a bug reported from one browser
  • Reading user agent strings out of server logs
  • Checking what your own browser reports
  • Identifying which crawler hit a page
  • Understanding analytics device categories

Frequently asked questions

Why does every browser say Mozilla?

A historical accident. Early servers checked for Mozilla before sending modern pages, so every browser added it to avoid being downgraded. The claim has been meaningless for decades and is still there because removing it would break old sites.

Can a user agent string be trusted?

No. It is freely editable by the client, and plenty of tools, privacy extensions and bots change it. Treat it as a hint for analytics and never as a security measure or an access control.

Should I detect browsers using the user agent?

Only as a last resort. Feature detection, which tests whether the thing you need actually exists, is more reliable and does not break when a new browser appears. User agent sniffing is how sites end up broken in browsers released after they were written.

What are client hints?

Structured headers that report browser, platform and device characteristics individually rather than as one sentence. They are the intended replacement for user agent sniffing and are shown here when your browser provides them.

Why is the version number sometimes frozen?

Browsers have begun reducing the detail in user agent strings for privacy, reporting a frozen major version and a generic platform. That is deliberate, and client hints are the supported way to ask for more.

Is my user agent sent anywhere?

No. Parsing happens in your browser, and nothing is logged.

If the user agent parser is not quite what you need, these other free tools solve closely related problems.

MIME Type Lookup

Look up MIME types by extension, or find which extensions use a type.

Developer Tools Use tool

Hash Generator

Generate cryptographic hashes of text, computed in your browser.

Developer Tools Use tool

Time Zone Converter

Convert times across time zones, with daylight saving handled correctly.

Utility Tools Use tool