What is TTFB?

Learn what TTFB (Time to First Byte) is, why it matters for SEO and user experience, and how to improve it for faster APIs.

TTFB (Time to First Byte) measures the duration from when a client makes an HTTP request to when it receives the first byte of the response. It includes DNS resolution, TCP connection, TLS handshake, and server processing time. Google recommends TTFB under 600ms for good Core Web Vitals. Use our <a href="/api-checker">API response checker</a> to measure your TTFB and identify bottlenecks.

Try It Now

Test your API performance instantly with our free tool. No registration required.

Millisecond-precision response times
DNS lookup & TTFB analysis
Support for all HTTP methods
Custom headers & body payloads
SSL certificate validation
Export results as JSON/CSV

Frequently Asked Questions

What does TTFB stand for?

TTFB stands for Time to First Byte — the time between sending a request and receiving the first byte of the response.

Why is TTFB important?

TTFB directly impacts user experience and is a Google ranking factor. High TTFB means users wait longer before seeing any content.

what is ttfbttfb explainedtime to first bytettfb meaningserver response time