HTTP Headers Viewer
View the exact HTTP request headers your browser is sending to web servers.
How Does the HTTP Headers Viewer Work?
Every time you visit a website, your browser sends an HTTP request to the server hosting that site. Included in this request are HTTP headers—invisible lines of text that transmit critical metadata about your browser, device, connection preferences, and previous interactions with the site. The server reads these headers to decide how to format the response and whether to grant you access.
This tool acts as a mirror, capturing the exact HTTP headers your browser just sent to our server and displaying them back to you in a readable format. Our backend API receives your request, extracts the raw header dictionary, and returns it as a JSON object. You can see standard headers like User-Agent, Accept-Language, and Connection, as well as custom headers that your ISP or corporate firewall might be injecting into your traffic.
Why is Header Analysis Important for Privacy?
HTTP headers are a major vector for browser fingerprinting and privacy leaks. The User-Agent string alone reveals your exact operating system version, device type, and browser build. The Accept-Language header reveals your preferred language and geographic locale. If a website wants to track you without cookies, the unique combination of these headers provides a highly accurate starting point.
Furthermore, examining your HTTP headers can reveal if your traffic is being intercepted or modified. Some mobile carriers and public Wi-Fi networks use transparent proxies that inject custom headers (like X-Forwarded-For) into your unencrypted HTTP traffic to track your browsing habits or optimize image compression. By reviewing your headers, you can verify if your VPN is successfully hiding your original IP from being leaked via proxy headers.
Frequently Asked Questions
Q: What is the User-Agent header?
A:The User-Agent is a string of text that identifies the browser, operating system, and device type you are using. Web servers use this to serve mobile-optimized sites to phones, or to block unsupported browsers.
Q: Can I change my HTTP headers?
A:Yes. You can use browser extensions (like User-Agent Switcher) to spoof certain headers. Additionally, privacy browsers like Tor standardize headers across all users so that the headers cannot be used to uniquely identify individuals.
Q: What is the X-Forwarded-For header?
A:X-Forwarded-For is a standard header used by proxies and load balancers to identify the original IP address of a client. If you are using a proxy server that doesn't strip this header, the destination website will still see your real IP address.
Q: Why do some headers start with 'sec-'?
A:Headers starting with 'sec-' (like sec-ch-ua) are part of the newer Client Hints API. They are designed to be a more secure, structured replacement for the messy User-Agent string, allowing servers to request specific device info rather than parsing a massive text block.