Ultrafast mode is up to 8x faster in Codex, but only Pro 500 and Enterprise can use it for now
Ultrafast is OpenAI's premium speed tier. Token generation is up to 8x faster in Codex (300 tokens per second) and up to 6x faster in the API. GPT-6 Astra Ultrafast opened today in the API, ChatGPT Work and Codex; on the product side it is limited to Pro 500 and Enterprise. GPT-6.1 Sol Ultrafast is coming soon. Sam Altman wrote that it is "so fast I do not ever want to go back," and the post passed 6,000 likes. You pick it in the model picker, and it draws on your plan's included usage first and credits after that. Buying credits on Pro 100 or Pro 200 does not unlock Ultrafast.