What is a TTFB checker?
A TTFB checker measures Time To First Byte — how long the server takes to send the first byte after a request. This free TTFB test lets you check TTFB for any URL and test TTFB online.
Diagnose & fix a slow server response
A high time to first byte delays everything after it, including LCP. Reduce it with caching and a CDN, faster hosting, optimized database queries, HTTP/2/3, and fewer redirects. Re-test after each change to confirm the improvement.
What's a good TTFB?
Aim for under 800ms (under 200ms is excellent). TTFB underpins your Core Web Vitals, so improving it speeds up the whole page.
More Core Web Vitals tools
Check the rest: LCP Checker, CLS Checker, INP Checker, and the full Page Speed Test.