User-Agent Info
User-Agent Info — runs in your browser. Inputs are not stored.
User agent info
Enter values, then press Calculate.
Shows only the browser’s navigator and screen info. Checked locally with no server request.
How to use
- When you open the page, navigator.userAgent plus platform, language, cookieEnabled, hardwareConcurrency, and viewport are filled in immediately.
- After you resize the window, press Refresh to update the viewport numbers.
- You can review the same values structured under JSON below.
- For remote support, Copy the JSON and send it.
- There is no send-to-server button. It only reads locally.
Key concepts
User agent info collects the string and screen hints the current browser reports. Use it for remote support, CSS media debugging, and checking whether cookies are enabled. It only reads navigator and screen data; there is no server request. These values alone cannot identify a person; they are debugging hints.
Modern browsers may shorten or nearly freeze userAgent for privacy. Platform and core count can also be hidden depending on the environment. Viewport is layout pixels and can differ from the device’s physical resolution. The JSON is a convenient shape to paste into an issue tracker.
Example
Narrow a desktop window and press Refresh: the reduced viewport width is reflected in the JSON. A profile with cookies blocked may show cookieEnabled as false. Sending copied JSON to a colleague means you do not have to describe the browser in words. For remote support, pasting the JSON avoids explaining the browser and viewport verbally. You must press Refresh after resizing for the viewport numbers to update. These values cannot identify a user; they are debugging hints. When trying the same input several times, reset and paste again so it does not mix with the previous output. On a shared computer, clear the field when you finish so the original is not left on the monitor. Closing the browser tab also discards what you just pasted; you do not need to send a delete request to a server. Button names and field titles match the tool at the top of the screen, so you can follow along as you read. If the result is empty, first check that required fields are filled and that an error message is not hidden. This article is usage guidance and does not mean input is kept in external storage. On mobile, the copy button may ask for clipboard permission; allow it and press again.
Related: My IP address
Frequently asked questions
Is user agent info sent to a server?
No. It only reads navigator and screen information locally.
When does the viewport update?
After you resize the window, press the Refresh button and the numbers change.
Can userAgent alone identify a device?
It is hard. Many strings are reduced or frozen, so treat them as hints.
What goes into the JSON?
The agent string plus platform, language, cookies, core count, and viewport.
Is hardwareConcurrency physical CPU cores?
It is a logical-core hint the browser reports. It can differ from physical cores.
Is language the same as the OS setting?
It follows navigator.language, so it is close to the browser UI language and can differ from the OS.
Last reviewed: 2026-09-04