Check Browser Info
Check Browser Info is a free online tool that shows every piece of information your browser reveals about itself: the user agent, the browser name and version, the operating system, the screen resolution and the device pixel ratio, the language and the time zone, the network connection, the battery, the graphics card, the supported audio and video formats, the permissions you granted, the installed fonts, your geolocation and the complete list of web features the browser supports.
Everything runs inside your own browser. No information is sent to a server, nothing is stored and nothing is shared. This is exactly the kind of data any website can read about you, which makes this tool useful to debug a website, to check if a feature is supported before using it, or simply to see how much your browser gives away.
How to use this online tool?
The information is read automatically when the page opens. Use the search box to filter the properties by name or by value, and use the buttons to copy everything to the clipboard or to download it as a TXT or a JSON file. To see your coordinates, click on the button "Detect my location" and allow your browser to share the location with this page.
Reading the information of your browser...
Geolocation
Your browser only shares your coordinates after you allow it, so this one is not read automatically.
The coordinates stay in your browser. They are never sent anywhere, and they are only included in the copy and download buttons above after you detect them.
What does your browser tell about you?
Every time you open a website, your browser hands over a surprising amount of information without asking you. Some of it is needed to show the page correctly, like the size of your screen or the languages you can read. The rest is a side effect of how the web grew over the years.
| Information | What it is used for |
|---|---|
| User agent | A text that identifies the browser, its version and the operating system. Websites use it to work around bugs of specific browsers, and it is the oldest way of detecting a mobile device. |
| Device pixel ratio | How many physical pixels the screen uses for each CSS pixel. On a high density screen this is 2 or 3, and websites use it to load sharper images. |
| Screen and window size | Used to choose a layout for phones, tablets or desktops, and to decide how many columns fit on the page. |
| Language and time zone | Used to translate the page and to show dates, times and numbers the way you are used to reading them. |
| Graphics card | Reported through WebGL, so that games and 3D applications can adapt their quality to the hardware. |
| Geolocation | The only item on this page that always requires your permission, because it points to where you physically are. |
| Supported features | Websites check whether an API exists before using it, so that an old browser gets a simpler version of the page instead of a broken one. |
Browser fingerprinting
Taken one by one, none of these properties identifies you. Taken together, they often do: the combination of your screen size, your fonts, your time zone, your graphics card and your list of supported features is frequently unique among millions of visitors. That combination is called a browser fingerprint, and it can be used to recognize a visitor even without cookies.
This is why modern browsers report less and less: the user agent is being frozen, the device memory is rounded, the plugin list is empty, and the names of your cameras and microphones stay hidden until you grant permission. If you want a smaller fingerprint, keep your browser updated, avoid installing unusual fonts and extensions, and use a browser that actively blocks fingerprinting.
Remember that this page reads only what the browser exposes to JavaScript. Information that comes from the connection itself, such as your IP address, is only visible to a server, and it is never read here.