An HTTP Checker That Explains the Answer

curl -I gives you the headers. This gives you the headers with a sentence under each one saying what it does, the redirect chain with a time per hop, and a grade for the parts that decide whether a page is fast, cacheable and safe.

What the Report Grades

Six sections, each marked pass, warning or fail, rolled into a score out of 100.

The headers guide goes through each header family with the value to send, and the status code reference covers when to use which 3xx, 4xx and 5xx.

How One URL Becomes a Report

Enter a URL and httpcheck.tools requests it from this server with the user agent you picked, following redirects itself one hop at a time so every hop's status, headers and timing are recorded, up to ten hops. The final response is then read six ways. The status section grades the chain. The headers section lists every header, grouped into content, caching, security, cross-origin, cookies, server and timing families, each with a plain-English line from a dictionary of about a hundred known headers. Caching reads Cache-Control, ETag, Last-Modified, Expires, Vary, Age and the CDN status as one system. Content checks the type, charset and whether compression was applied. Security notes which of the six standard headers are present. Timing splits the final hop into DNS, connect, TLS and time to first byte, and reads the certificate.

Paste several URLs and the tool switches to bulk mode: up to 25 URLs fetched in parallel, one row each with the first status, the final status, the hop count, the final URL, type, Cache-Control and server. It is the fastest way to check a list of old URLs after a migration.

What a single fetch cannot see

Timings are measured from this server's network, so they show the server's speed, not your visitors' experience from their locations. Sites that vary their answer by region, cookie, login or device show what an anonymous visitor from here gets; the user-agent selector covers the common cases (Chrome, iPhone Safari, Googlebot, curl). Headers added by a CDN only for certain paths, cache states that change with traffic, and anything JavaScript does after load are outside one request. The security section reports presence only; the values are graded on our sister site securityheaders.tools.

When an explanation is wrong

If a header explanation is wrong or missing, the contact page says what to send. The report page carries the URL in its address, so a report can be shared by copying the link.