Browser & Web Performance · Junior · Question 20 of 75

What does TTFB (Time to First Byte) measure?

✓Correct answer: The time from the start of navigation until the first byte of the response arrives
2The time until the first image is painted
3The size of the first network packet

Explanation

TTFB includes redirects, DNS, connection setup and server processing. A slow TTFB delays every later metric, including LCP.

Further reading

web.dev: Time to First Byte (TTFB) ↗

Test yourself

Take the Browser & Web Performance · Junior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.