Time to First Byte is fast

high

ttfb

Last updated: 2026-07-29

Checks that Time to First Byte is fast.

What does this rule check?

TTFB measures the time from the request to the first byte of the response. It reflects server processing time, network latency, and caching effectiveness. Target is under 800ms, ideally under 200ms.

Why is this important?

Slow TTFB delays everything — the page cannot start rendering until the first byte arrives. It's a direct Core Web Vitals metric and affects user-perceived performance.

How to fix

Optimize server-side processing, enable caching, use a CDN, and optimize database queries.

Examples

Incorrect

TTFB: 3.2 seconds
<!-- Server is slow to respond -->

Correct

TTFB: 150ms
<!-- Fast server response with caching -->

Agent fix snippet

Copy this snippet and paste it into your AI coding agent to fix this issue automatically.

Improve TTFB:
1. Enable server-side caching (Redis, Memcached)
2. Use a CDN for static assets
3. Optimize database queries
4. Consider SSG for static content
5. Enable HTTP/2