What Is TTFB (Time to First Byte)?

What TTFB actually includes

TTFB is the sum of several stages that happen before any content arrives:

• DNS lookup — resolving the domain to an IP.
• TCP connection — the handshake to open the connection.
• TLS negotiation — the HTTPS handshake (for secure sites).
• Request send + server processing — the server building the response.
• Waiting — until that first byte comes back over the wire.

What's a good TTFB?

• Under 200 ms — excellent.
• 200–500 ms — acceptable for most sites.
• 500–800 ms — slow; worth investigating.
• Over 800 ms — a problem that hurts user experience and rankings.

Why it matters

TTFB is the floor for how fast a page can possibly feel — nothing renders before the first byte. A high TTFB delays everything downstream. Search engines also treat server responsiveness as a signal, so a slow TTFB can quietly cost you both users and ranking.

How to reduce it

Measuring TTFB from several locations separates network distance from server slowness: if TTFB is low nearby but high far away, the network is the cost; if it's high everywhere, the server is.

• Cache responses so the server skips repeat work.
• Use a CDN to serve users from a nearby edge, cutting network distance.
• Optimise slow database queries and backend code.
• Reuse connections (keep-alive, HTTP/2) to avoid repeated handshakes.
• Host closer to your users, or add regional points of presence.