GATE 06 · HTTP HEADERS
What your browser sends
Quick answer: HTTP headers are small labels your browser attaches to every page request, describing your browser, operating system, preferred languages and accepted content. This tool lists the headers your browser sent to this site, with a short explanation of each, so you can see what any website could learn without asking.
Reading your headers…
Every request your browser makes carries headers: small labels that describe your browser, language and where you came from. Websites can read all of them.
This list comes from a background request made by this page, so a few entries (such as Accept and the Sec-Fetch headers) differ slightly from a normal page load. Cookie values are never shown. Headers added by our own server are left out.
What are HTTP headers?
Every time your browser asks for a page, it attaches a set of small labels called HTTP headers. They describe your browser and operating system, the languages you prefer, what kinds of content you accept, and sometimes the page you came from. Websites read them automatically and can store them.
This tool shows the headers your browser sent to this site, with a short explanation of each one. It is a quick way to see what any website could learn about you without asking.
Headers that reveal the most
- User-Agent: your browser name, version and operating system.
- Accept-Language: the languages you have set, which hints at where you live or where you are from.
- Referer: the page you were on before, when your browser sends it.
- Sec-CH-UA headers: extra detail about browser and device, called client hints, sent by Chromium-based browsers.
- Cookie: stored identifiers. The tool shows only that cookies were sent, never their values.
- Sec-GPC: shows that you turned on Global Privacy Control, a request not to sell your data.
Why it matters
No single header identifies you. Together, though, browser version, operating system, language and screen-related hints can make your browser fairly unique, which is called fingerprinting. A VPN or proxy changes your IP address but does not change these headers, so the same browser can be recognised on a new address.
Some proxies also add their own headers, such as Via or X-Forwarded-For, which can reveal that a proxy is in use or pass on your real address.
How to share less
Use a browser with built-in tracking protection, or turn on its fingerprinting protection. Firefox offers resist fingerprinting in about:config. Keep your language list short. Turn on Global Privacy Control where your browser has it. Limit referrer information in your browser's privacy settings. Note that the list on this page comes from a background request, so a few entries, such as Accept and Sec-Fetch, differ from a normal page load.
Frequently asked questions
What is a User-Agent?
It is a header that names your browser, its version and your operating system. Websites use it to serve the right version of a page. Chrome and some other browsers now shorten it to share less detail.
Can websites see my headers?
Yes. Every site you visit receives them automatically. This tool shows you the same information.
Does a VPN hide my headers?
No. A VPN changes your IP address, not the headers your browser sends. Your browser, system and language settings still travel to each site.
What does Sec-Fetch-Site mean?
The Sec-Fetch headers tell a server how a request was started, for example from the same site or from another one. Browsers add them automatically for security, and they do not identify you.
Why does this list differ from a normal page load?
The list comes from a background request made by this page, so entries such as Accept and Sec-Fetch can differ slightly. Headers added by our own server are left out.
Are my cookie values shown or stored?
No. The tool only shows that a cookie header was present. The values are never returned or stored.