BROWSER USE

- Browser Use Agents: give Browser Use a task and receive completed work. API V4 is current for new integrations.
- Browser Infrastructure: connect your agent or automation to managed browsers through SDK, REST, or CDP. Starts at $0.02/browser-hour.
- Developer tools: Open Source, Browser Harness, SDK, and MCP support the two products above.

[Developer Index](https://browser-use.com/index.md)
[Product Map](https://browser-use.com/llms.txt)
[Full Product Context](https://browser-use.com/llms-full.txt)
[Pricing](https://browser-use.com/pricing.md)
[Cloud Docs](https://docs.browser-use.com/cloud/quickstart)
[Open Source Docs](https://docs.browser-use.com/open-source/introduction)

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# What is my user agent?

> Your user agent is the string your browser sends to identify itself: name, version and OS. The tool on the HTML page reads `navigator.userAgent` and `navigator.userAgentData` in the visitor's own tab and parses them. The tool sends and saves nothing; the browser already sends the string as the User-Agent header, and site analytics log the page view as usual. This Markdown twin cannot read a user agent.

[HTML page](https://browser-use.com/tools/what-is-my-user-agent) · [Bot detection test](https://browser-use.com/tools/bot-detection-test) · [Random user agent generator](https://browser-use.com/tools/random-user-agent)

## What the tool shows

- The full `navigator.userAgent` string, with a copy button.
- Parsed from that string: browser, version, engine, device type, operating system. Frozen values are labelled, for example `macOS (frozen at 10.15)` ([Chromium](https://www.chromium.org/updates/ua-reduction/)) or `iOS 18.6 or later (frozen)` ([WebKit](https://bugs.webkit.org/show_bug.cgi?id=298260)).
- Client hints from `navigator.userAgentData`: brands, platform, mobile. High-entropy values (architecture, bitness, model, platform version, full version list) only after a button click. Firefox and Safari do not expose `navigator.userAgentData` ([MDN](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/userAgentData)).
- On Windows, the Windows version from `platformVersion`: 1 to 10 is Windows 10, 13 and above is Windows 11, 0 is Windows 7, 8 or 8.1 ([Microsoft](https://learn.microsoft.com/en-us/microsoft-edge/web-platform/how-to-detect-win11)).

## What each part means

Chrome's desktop format ([Chromium](https://www.chromium.org/updates/ua-reduction/)):

`Mozilla/5.0 (<unifiedPlatform>) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/<majorVersion>.0.0.0 Safari/537.36`

| Part | Meaning |
|---|---|
| `Mozilla/5.0` | Legacy token (see FAQ). |
| `(Windows NT 10.0; Win64; x64)` | Operating system. Chrome freezes it: Windows 11 still says NT 10.0, macOS always says `10_15_7`, Android always says `Android 10; K` ([Chromium](https://www.chromium.org/updates/ua-reduction/)). |
| `AppleWebKit/537.36 (KHTML, like Gecko)` … `Safari/537.36` | Compatibility tokens. Constant in Chrome's reduced format ([Chromium](https://www.chromium.org/updates/ua-reduction/)). |
| `Chrome/<major>.0.0.0` | Browser and major version. Chrome on desktop and Android sends `0.0.0` for the rest ([Chromium](https://www.chromium.org/updates/ua-reduction/)). |

## FAQ

**Why does Chrome report Mozilla/5.0?** A compatibility token kept for historical reasons. Almost every browser sends it ([MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/User-Agent)).

**Is my user agent unique?** Not by itself in Chrome: everyone on the same major version, OS and device type sends the same string ([Chromium](https://www.chromium.org/updates/ua-reduction/)). Combined with other signals it can still feed fingerprinting ([MDN](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/User-Agent)).

**How do sites detect bots beyond the user agent?** They check other signals, such as [`navigator.webdriver`](https://developer.mozilla.org/en-US/docs/Web/API/Navigator/webdriver) and the [TLS fingerprint](https://developers.cloudflare.com/bots/additional-configurations/ja3-ja4-fingerprint/). See the [bot detection test](https://browser-use.com/tools/bot-detection-test) and the [random user agent generator](https://browser-use.com/tools/random-user-agent).