TTFB · Server response time
TTFB (Time To First Byte) is the delay between the request and the first byte received. A high TTFB penalizes crawling and, mechanically, AI crawlers’ access to content: a slow server reduces the number of pages retrieved in the time allowed.
Standalone definition · 41 words
What does TTFB measure?
It aggregates DNS resolution, connection, server processing and the start of the response. web.dev considers a TTFB of 0.8 seconds or less good and above 1.8 seconds poor. It is not a Core Web Vital, but it conditions LCP.
How do you improve it?
Page cache and CDN, a faster or better-sized server, optimized database queries, compression, HTTP/2 or HTTP/3, fewer redirects and edge caching of HTML. On WordPress, a page cache avoids regenerating every request.
TTFB, crawling and AI bots
Google says crawl capacity depends on server responsiveness. High delays or errors reduce the crawl rate. For AI bots, logs show response times and the error codes to watch, especially behind a CDN or firewall.
Frequently asked questions
Is TTFB a ranking factor?
Not directly. It influences LCP and crawling.
Which tool measures it?
PageSpeed Insights, CrUX and network testing tools.
SSR and TTFB: what is the link?
Server rendering can increase it; a cache or CDN limits the effect.
Related terms
Further reading
- Checklist GEO and LLM / AI 2026
- 2026 GEO Tools Comparison: The Decision Guide
- ← Back to the GEO glossary (114 terms)