TTFB Checker

TTFB Checker measures how long a site takes to return the first byte of a response, and shows the headers that explain the number.

A browser cannot make this measurement itself, because a cross-origin page will not let JavaScript read another site's timing or headers. The request is made by a ShortTrick server route instead, so the figure is the latency between that server and the site rather than between you and the site — a host physically near you can read slower here than it feels in your own browser. Alongside the timing you get the HTTP status, the Server header, Cache-Control, whatever CDN cache-status header the response carried, and the number of redirect hops, since a redirect chain is a common hidden cause of a slow first byte.

The URL you enter is sent to ShortTrick's own server, which fetches that page and returns what it observed; it is not handed to any third-party measurement service. The site under test sees a request identifying itself as ShortTrickSEOInspector, so the check appears in its access log.

Deciding whether a slow page is slow at the server or in the browser, confirming a CDN is serving a cached copy, counting the redirect hops behind a vanity URL, and comparing two hosts before a migration.

Also known as: time to first byte tester · server response time test · website latency checker · check ttfb · ttfb test · test ttfb