HTTP headers
Inspect any URL's headers
Status code, redirect chain, and every response header, fetched live.
Redirect chain
| Name | Value |
|---|
What HTTP headers are
Every time a browser asks for a page, the server answers with a status code and a set of headers before any content. Headers tell the browser what it received, how long to keep it, which security rules apply and whether to go somewhere else instead. They are invisible on the page but shape how it loads.
- content-type
- What the response is, such as text/html or application/json, and often its character set.
- cache-control
- How long browsers and CDNs may keep a copy before asking again, or whether they may keep one at all.
- strict-transport-security
- Tells browsers to use HTTPS only for this site for a set time, so a mistyped http:// link is upgraded automatically.
- location
- Sent with a redirect. It holds the address the browser should go to next.
A redirect chain is the list of hops between the address you typed and the page you end up on, for example from http:// to https:// and then to www. Each hop is another round trip, so a long chain slows the first visit, and search engines may stop following it. One or two hops is normal; more usually means old redirects were stacked on top of each other.
Frequently asked questions
Headers are short name and value pairs a server sends before the page itself. They describe the response: its type, how long it can be cached, security rules, cookies and where to go next if it is a redirect.
Both are redirects. A 301 says the page has moved permanently, so browsers and search engines should use the new address from now on. A 302 says the move is temporary, so the old address stays the main one.
This tool fetches the URL server to server, without your cookies, login or browser details. Many sites send extra headers only to logged-in visitors or to specific browsers, and devtools also shows headers your browser added itself.
Yes. Response headers are sent to every visitor who opens the page, so they are public by design. This tool makes one ordinary request, the same as opening the link.
The most common reasons are a mistyped URL, a domain that doesn't exist, a server that took longer than 10 seconds, or a host we won't contact because it points to a private or local network address. Too many redirects in a row also stops the check.
No. The URL is used for the one request and then discarded. Nothing is logged by us, and nothing is saved in your browser either, so there's no history to clear.