GPT-6.1 Sol gets an Ultrafast mode in the Responses API at six times the standard price
Paying for speed: the same model, with a faster output tier chosen per request.
// Key points
- Calling gpt-6.1-sol with service_tier: "ultrafast" reduces the time between generated output tokens.
- It is available to all API users, subject to rate limits, with global processing and US and EU data residency.
- Pricing for up to 272K input tokens, per million tokens: Ultrafast is $12 input, $0.60 cached input and $60 output, versus $2, $0.10 and $10 on the standard tier.
Builder's takeSix times the price is only worth it where a user is watching the screen, like real-time follow-up questions in AI Interview; batch jobs don’t need it. Since the tier is chosen per request, I’d enable it on that one path only, compare time to first token and total time, then work out the extra cost per interview.