What is TTFB (Time to First Byte)?
Turkish: TTFB
TTFB measures the time from sending a browser request to receiving the first response byte, exposing server and network delay.
What is TTFB?
TTFB (Time to First Byte) shows how long it takes a browser to receive the first byte from the server after requesting a page. The duration can include DNS lookup, connection setup, TLS negotiation, server processing, and network distance.
Why Does It Increase?
Common causes of high TTFB include:
- Slow database queries or missing indexes
- Heavy server-side rendering
- Cold starts in serverless functions
- Origin servers far from users
- Low cache hit ratio
- Excessive redirect or proxy chains
How Is It Improved?
Serving static assets through a CDN, using server-side cache, optimizing database queries, rendering at the edge, and removing unnecessary middleware can lower TTFB. The target is not identical for every page; a personalized dashboard and a static article have different response models.
TTFB is not one of the Core Web Vitals, but it is an important diagnostic signal because it can influence user-facing metrics such as LCP.