Yall want to see instant? Check out chatjimmy.ai blow your mind. I’m not affiliated.
But the things it unlocks in a product I’m building are mind blowing. Millisecond inference even on much older models will change the whole game. Enough to run inference on every. Single. API call. Without notable disruption. This sh*t is wild.
Good question. I find that GPT-5.5 thinking is very good at not thinking for simple questions, so much so that I've never had the need to use the instant model even for quick Q&A.
I'm assuming the instant model, then, is an entirely different smaller model mainly serving the free tier of ChatGPT.
Good point. I feel like this does a disservice to ChatGPT -- IIRC even the free tier of Claude points you to Sonnet 4.6 by default, which is magnitudes better than 5.3-instant which has been the default in ChatGPT.
Hence most users will immediately think Claude is smarter, even if their best models are on par.
Correct. I have the $20/month plan and I just checked, the default is 5.3-instant. I can manually switch it to Thinking is 5.5. I also have it set to auto-switch.
Why can't they be more consistent about releasing the Insant and Thinking models at the same time for each version number? Why all this duplicative drama?
It's probably a modified version of the thinking model. If that's the case, releasing them at the same time would mean delaying the thinking model's release.
But the things it unlocks in a product I’m building are mind blowing. Millisecond inference even on much older models will change the whole game. Enough to run inference on every. Single. API call. Without notable disruption. This sh*t is wild.