See every HTTP header your browser sends with each request — user agent, accepted languages, encoding, cookies and more.
HTTP headers are the metadata your browser attaches to every request: what content types it accepts, which languages it prefers, whether it has cookies for the site, and the user agent string that identifies the browser. Most of this is invisible — you never see it unless you open the developer tools.
This tool calls getallheaders() on the server and renders the result as a table. It shows exactly what the server on the other end receives, which is useful when debugging a proxy, a CDN, a caching layer or a CORS issue. If Cloudflare or another reverse proxy is in front, you see the headers it adds too.
The headers are read and displayed in one request. Nothing is stored, forwarded or logged — the page renders them and forgets.
No. They are read from the request and rendered in the HTML. Nothing is stored.
Because proxies, CDNs and browser extensions can add headers. Cloudflare adds CF-Connecting-IP and CF-Ray, for example.
It tells the server which languages your browser prefers, in order of priority. Sites that support multiple languages use it to pick the default.
Some, through browser settings or extensions. The User-Agent can be overridden, Accept-Language follows your OS language settings, and a VPN or proxy changes the forwarding headers.
Almost. The developer tools show request and response headers; this page shows only the request headers as the server sees them, which may include additions from infrastructure the browser does not know about.
Vai.la turns any URL into a short link with click statistics, QR Code and your own biolink.
Vai.la is not responsible for how the tools are used or for decisions made based on their results.