Measure DNS lookup, TCP connect, SSL handshake, TTFB and download time. Graded A–F by response speed.
Time to resolve the hostname to an IP address.
Time to establish a TCP connection with the server.
Time to negotiate the TLS/SSL session for HTTPS.
Time To First Byte — the primary performance indicator. Used to calculate the grade.
Page speed directly impacts user experience and SEO rankings. Google uses Core Web Vitals as ranking signals. Our performance tester measures DNS lookup time, TCP connect, SSL handshake, Time to First Byte (TTFB), and download speed — graded A through F.
Time to First Byte (TTFB) measures how long it takes for the browser to receive the first byte of response after a request. Under 200ms = excellent. Over 600ms = poor. It's the primary server-side performance metric.
Common causes: slow server-side processing (database queries, heavy PHP/Python), no caching, shared hosting bottlenecks, or distant server location from users. Use server-side caching (Redis, Memcached, OPcache).
Every page load starts with DNS resolution. Slow DNS (>100ms) adds latency before any connection is made. Use fast DNS providers (Cloudflare 1.1.1.1, Google 8.8.8.8) and enable DNS caching.
Aim for A (TTFB < 200ms). B is acceptable. C/D indicate server-side performance issues. F indicates serious problems. Most optimizations target TTFB first, then asset loading.