Performance

Time to first token

Q: What does TTFT stand for?

TTFT stands for Time to first token. How long after you send a prompt before the very first token of the answer appears. The main driver of how responsive a streaming reply feels.

TTFT

How long after you send a prompt before the very first token of the answer appears. The main driver of how responsive a streaming reply feels.

In practice

A 200ms TTFT feels instant; two seconds feels sluggish even if the full answer is fast.

Related terms

Streaming Latency Tokens per second

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