AI & the web
Time to First Byte
The elapsed time from requesting a resource to receiving its first response byte.
In everyday use
A browser waits before the server begins returning a page.
What to keep in mind
It includes more than application processing and is not full load time.
Also searched as: TTFB
Further reading
Original explanation and example by Perspectism. Further reading may cover the wider subject, rather than this exact wording. Edition updated 7 October 2026.
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