TTFB checker

Free TTFB Checker — Measure Time to First Byte

Time to First Byte (TTFB) is the gap between a browser sending a request and receiving the first byte of the response. Enter any URL and this tool measures it — the single number that sits underneath every other speed metric on your site.

TTFB matters because it's the foundation everything else is built on. If your server takes 800ms to start responding, then your Largest Contentful Paint, your rendering and every visible element are all delayed by that 800ms before any front-end optimization even begins. A good TTFB is under 200ms at the 75th percentile; many sites sit far higher because they render uncached pages on every request or serve from a single distant server. Because Core Web Vitals influence ranking and slow pages lose conversions, TTFB is one of the highest-leverage things to fix.

Three things drive it: network distance (fix with a CDN), server processing time (fix with caching), and the connection protocol (HTTP/3 and HTTP/2 beat HTTP/1.1). Use this tool to benchmark your current TTFB, to confirm a caching or CDN change actually helped, and to catch regressions after a deploy. If the number is high, that's usually where your speed problems begin.

From one check to a complete audit

This tool checks one thing. Smart SEO Audit checks 50+ — technical, on-page, content and speed — on any URL in under 10 seconds, with an AI-prioritized fix list, scheduled monitoring and Swiss, GDPR-compliant hosting. Start free — 5 full audits a month, no credit card.