Edit: looks like this is still GPT-3, just fine tuned. They claim the model is available via ChatGPT Plus, but when asking that model for it's version, it claims to be GPT-3: "I am a variant of the GPT architecture called GPT-3, which was released by OpenAI in 2020".
> ChatGPT Plus subscribers will get GPT-4 access on chat.openai.com with a usage cap. We will adjust the exact usage cap depending on demand and system performance in practice, but we expect to be severely capacity constrained (though we will scale up and optimize over upcoming months).
Edit: looks like this is still GPT-3, just fine tuned. They claim the model is available via ChatGPT Plus, but when asking that model for it's version, it claims to be GPT-3: "I am a variant of the GPT architecture called GPT-3, which was released by OpenAI in 2020".