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TTFB test
Time to First Byte is how long the server takes to start answering — the wait before anything else can happen. Here it is for real visitors, and from one lab run.
Why TTFB is slow
- No caching in front of the page
- Every request rebuilds the page on the server. A CDN or full-page cache answers repeat requests in tens of milliseconds.
- Slow work on the server
- Database queries, API calls or template rendering that run before the first byte is sent. Profile the slowest route first.
- Distance
- A server in one region is far from visitors in another. A CDN or edge rendering moves the first byte closer to them.
- Redirects
- Each redirect (http → https, bare domain → www) is a full round trip before the real request even starts.
- Cold starts
- Serverless functions that sleep between requests pay a start-up cost on the first one. Low-traffic sites feel it most.
TTFB changes with every deploy and every traffic spike.
Paste one script and we record TTFB for every real visit, by page, country and connection — and tell you which release made it slower.
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