Browser & device
What is my user agent?
This is how your browser introduces itself to every website you visit.
Your user agent
What it says about you
Client hints Chrome, Edge & other Chromium browsers
What is a user agent?
Every time your browser asks a website for a page, it sends a short line of text called the user agent. It names the browser, its version and the operating system, so the website can send pages that work well on your device.
The string often looks confusing – almost every browser still starts with Mozilla/5.0 and mentions other browsers like Safari or Gecko. This is for historical compatibility: old websites checked for those words, so new browsers kept them.
Why do newer browsers show less detail?
Chrome, Edge and other Chromium browsers now "freeze" parts of the user agent (for example the Windows version and the exact browser build) to reduce fingerprinting. The full details are available through client hints, which a website has to ask for. That is why Windows 11 often appears as "Windows NT 10.0".
Can I change my user agent?
Yes. Developer tools in most browsers can override it for testing, and some extensions do it permanently. Be aware that an unusual user agent can make you easier to recognise, not harder.
Decoding a user agent string
Here is a typical desktop Chrome user agent, broken into parts:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36Mozilla/5.0– a historical token every browser sends for compatibility. It means nothing today.Windows NT 10.0; Win64; x64– the operating system and architecture.AppleWebKit/537.36 (KHTML, like Gecko)– another compatibility token, frozen for years.Chrome/130.0.0.0– the browser and its major version. Minor version numbers are reduced to zeros to limit fingerprinting.Safari/537.36– again for compatibility. Microsoft Edge addsEdg/…at the end, and Opera addsOPR/….
Which client hints a site receives
With User-Agent Client Hints, by default a site gets low-detail hints such as Sec-CH-UA (brand and major version), Sec-CH-UA-Mobile and Sec-CH-UA-Platform. It must explicitly request higher-detail hints like the full version or platform version. The panel above shows which hints your browser provides.
When you need your user agent
- Support requests: developers often ask for it to reproduce a bug. Copy it from this page.
- Testing websites: developer tools in every major browser can simulate other devices, which changes the user agent and screen size together.
- Server logs and analytics: user agents tell you which browsers your visitors use, and help identify bots.
Your user agent is one part of your browser fingerprint – see how unique the whole picture is with our browser fingerprint test.
User agent – frequently asked questions
Why does my iPad say it is a Mac?
Since iPadOS 13, Safari on iPad requests desktop websites by default and sends a macOS user agent. Websites can usually still tell it is a touch device through other signals.
Can a user agent prove what browser someone uses?
No. It is just text the browser sends and can be changed easily, so it should never be used for security decisions.