The AI Models Index keeps you up to date on premium releases from 15 labs since...

https://technivorz.com/how-long-does-google-take-between-announcing-and-shipping-a-model/

The AI Models Index keeps you up to date on premium releases from 15 labs since 2023, with verified launch dates and blind-vote accuracy checks. Updated every two weeks, it shows how models like GPT-5.2 improve 56% over GPT-5.1 on average