HTTP Headers Checker
View all HTTP response headers for a URL, with notes on the ones that matter for SEO.
About the HTTP Headers Checker
HTTP headers are metadata the server sends before the page itself. They can decide whether a page is indexed (X-Robots-Tag), how long browsers and CDNs cache it (Cache-Control), whether it is compressed (Content-Encoding), which canonical URL applies (Link) and how secure it is.
Because headers are invisible in the browser, problems hide here – a forgotten X-Robots-Tag: noindex from staging, missing compression or caching that serves stale pages. This tool shows the raw headers exactly as the server sends them and highlights the ones that matter for SEO and performance.
Frequently asked questions
Can headers block indexing?
Yes. X-Robots-Tag: noindex works like a robots meta tag and is the only way to noindex non-HTML files such as PDFs.
What is a good Cache-Control for HTML?
For pages that change, short caching such as “max-age=0, must-revalidate” or a few minutes at the CDN. Static files with versioned names can be cached for a year.
Why do I see different headers in my browser?
Servers and CDNs can vary responses by user agent, cookies, location or compression support.