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Some notes on GPT-5.1, which is now available in the OpenAI API

The new reasoning options are interesting, but the pelican feels like a bit of a regression from GPT-5 simonwillison.net/2025/Nov/13/…

in reply to Simon Willison

that forced reasoning was slowing down gpt5 a lot. I’m looking forward to test how this 5.1 performs now. PD: i laugh so hard about the pelicans benchmark yesterday