TTFB Checker

What is TTFB?

TTFB stands for Time To First Byte, and is the time that browser waits for server to respond with the first byte.

How to calculate TTFB with cURL?

Use the following cURL command to get the timing information about a given URL.

$ curl -o /dev/null -w "pretransfer: %{time_pretransfer} | starttransfer: %{time_starttransfer}"

# pretransfer: 0.272 | starttransfer: 0.345

Then calculate the time to first byte using the formula:

starttransfer - pretransfer = ttfb

# 0.345 - 0.272 = 0.073 sec
# 0.073 * 1000 = 73 ms

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