About the HTTP Header Checker
HTTP headers are instructions sent before a page's content, and several affect SEO directly. This HTTP header checker requests a public URL from our server, follows redirects and shows the final response headers, explaining each important one: X-Robots-Tag and Link (canonical) for indexing, Cache-Control, ETag, Last-Modified and Content-Encoding for speed, and Strict-Transport-Security, Content-Security-Policy and similar headers for security.
Headers are easy to miss because they do not appear in the page source. A stray X-Robots-Tag: noindex set by a server rule or plugin can keep pages out of search while the HTML looks fine. Use the checker when diagnosing indexing problems, confirming caching and compression after a server change, or reviewing security headers.
How to use it
- Enter a public URL.
- Review the status code and the full list of response headers.
- Read the explanations for SEO, caching and security headers.
- Change server, CDN or plugin settings to fix problems.
Frequently asked questions
Which HTTP headers matter for SEO?
The most important are the status code, X-Robots-Tag (which can set noindex or nofollow), Link with rel=canonical, Location on redirects, and Content-Type. Caching and compression headers affect speed, and Vary can matter for sites serving different content to different devices.
What is X-Robots-Tag?
X-Robots-Tag is an HTTP header that gives the same instructions as a meta robots tag, such as noindex or nofollow. It is useful for non-HTML files like PDFs and images, but it can also block HTML pages unintentionally if a server rule is misconfigured.
Are security headers a ranking factor?
Google has not said security headers like Content-Security-Policy are ranking factors. HTTPS is a lightweight signal, and HSTS helps enforce it. Security headers mainly protect visitors from attacks, which is worthwhile in itself. Test changes carefully, because a strict Content-Security-Policy can block scripts and styles your pages rely on.