The time from your request to the AI's first word.
TTFT is the awkward pause before a friend finally says, “Well...” The longer it lasts, the more you stare at the typing dots.
It decides when a chat or coding helper starts replying. A fast first word makes the AI feel quick.
Prefill
Prefill often causes most of the wait for the first word.
Inference engine
A faster inference engine can bring the first word sooner.
Continuous batching
Continuous batching changes the line for requests. This can change TTFT.