TTFB (Time to First Byte)
The time between requesting a page and receiving the first byte of response.
What is TTFB (Time to First Byte)?
Time to First Byte (TTFB) measures how long it takes for a user's browser to receive the first byte of response from a server after making an HTTP request. It includes DNS lookup, TCP connection, TLS negotiation, and server processing time.
A slow TTFB indicates server-side issues and can delay all other performance metrics. It's a key indicator of backend performance and hosting quality.
Why TTFB (Time to First Byte) matters
TTFB sets the baseline for all other loading metrics. A slow TTFB delays LCP and other Core Web Vitals. Server performance directly impacts user experience and can't be offset by frontend optimizations.
How to implement
Use a quality hosting provider
Implement server-side caching
Use a CDN to reduce network latency
Optimize database queries
Enable keep-alive connections
Consider edge computing for dynamic content
Common mistakes to avoid
- Choosing cheap, slow hosting
- Not using caching effectively
- Running expensive operations on every request
- Not using a CDN for global audiences
Examples
Good TTFB: Under 200ms
Acceptable TTFB: 200-500ms
Poor TTFB: Over 600ms
Frequently asked questions
Under 200ms is excellent, under 500ms is acceptable. Over 600ms needs improvement and will negatively impact other performance metrics.
CDNs serve content from geographically closer servers, reducing network latency. They can also cache responses at the edge, avoiding origin server round-trips.