What Is Time to First Byte (TTFB) and How Does CMS Affect It?
IntermediateQuick Answer
TL;DR
Time to First Byte (TTFB) measures how long it takes for a browser to receive the first byte of a server response after making a request. CMS choice directly affects TTFB through server processing time, database query efficiency, caching configuration, and hosting infrastructure. Traditional CMS platforms that render pages dynamically on each request typically produce higher TTFB than headless setups serving static pages or cached API responses from a CDN edge.
Key Takeaways
- TTFB is a Core Web Vitals diagnostic metric; Google recommends keeping it under 800ms as of April 2026
- Dynamic CMS rendering (PHP, database queries, template assembly) adds 100–500ms or more to TTFB on uncached requests
- CDN caching reduces TTFB to single-digit milliseconds for cached responses
- Headless CMS architectures with static generation eliminate server-side CMS processing from the delivery path entirely
- Hosting geography matters: a server in the US serving users in Asia adds 150–300ms of network latency alone