The AI Models Index keeps track of premium releases from 15 labs since 2023,...

https://alexisqoem867.trexgame.net/how-do-i-tell-if-an-ai-model-was-announced-or-really-shipped

The AI Models Index keeps track of premium releases from 15 labs since 2023, verified with blind-vote checks and accurate dates. Updated every two weeks, it shows how model development speeds up—GPT-5.2 launched just 4.5 days after GPT-5