HTTP headers checker

The HTTP headers checker shows exactly what a server answers to a request for a page: the status code, the whole redirect chain and all headers of every response. This is what a browser or a search robot sees before the content is loaded.

What response headers are

For every request the server sends a status line (e.g. HTTP/1.1 200 OK) and a set of Name: value headers: content type, charset, caching rules, cookies, redirect target and more. Example:

HTTP/1.1 301 Moved Permanently
Location: https://example.com/
Cache-Control: max-age=3600

Status codes

Code	Meaning
200 OK	request succeeded, page returned
301 Moved Permanently	permanent redirect: search engines move ranking and index to the new URL
302 Found / 307	temporary redirect: the old URL stays in the index
304 Not Modified	unchanged, the browser uses its cache
404 Not Found	no such page
410 Gone	page removed permanently
500 / 502 / 503	server error, proxy error or temporary unavailability

Redirect chains

If a URL redirects several times (http → https → www → trailing slash), each hop is an extra request and delay, and search engines may not follow a long chain to the end. The tool shows all responses in order (Response#1, Response#2…), so extra hops are visible immediately. Ideally there is a single 301 straight to the final URL.

Cache headers

Cache-Control — how long and where to store the response: max-age=31536000, immutable for static files, no-store for private data.
ETag and Last-Modified — the resource version: the browser revalidates and gets a short 304.
Expires — the legacy alternative to max-age.

Security headers

Strict-Transport-Security (HSTS) — the browser uses only HTTPS for the site.
Content-Security-Policy (CSP) — where scripts, styles and images may load from; protects against XSS.
X-Frame-Options: DENY or SAMEORIGIN — forbids showing the site in a frame (clickjacking).
X-Content-Type-Options: nosniff, Referrer-Policy — two more headers worth enabling.

Why check them

SEO — make sure a move uses 301, not 302, that there are no chains or loops, that pages return 200 and removed ones 404/410.
Caching — check that static files are cached and HTML and private pages are not.
Debugging — charset (Content-Type: text/html; charset=utf-8), compression (Content-Encoding: gzip), cookies, CORS, server version.
How robots see the site — some sites answer differently depending on the User-Agent.

User-Agent

You can send the request as your own browser, popular browsers (Chrome, Opera, Firefox, Internet Explorer, Opera Mini), search robots (YandexBot, GoogleBot, BingBot, Yahoo! Slurp, WebAlta Crawler), wget or with no User-Agent at all — or type your own string. This checks whether the server gives robots a different answer (cloaking) and whether mobile redirects work.

How to use the page

Enter a URL, e.g. https://example.com.
Choose a User-Agent from the list or type your own.
Press "Execute" — all responses of the chain appear with their headers.