GPT-5.5 Instant
GPT-5.5 Instant replaces GPT-5.3 Instant as the default model for all ChatGPT users and in the API as chat-latest. It produced 52.5% fewer hallucinated claims than GPT-5.3 Instant on high-stakes prompts covering medicine, law, and finance, and reduced inaccurate claims by 37.3% on conversations users flagged for factual errors.
The call on this one
What shipped is free. The call on it, what to do about it and the condition on that, opens with a signup: free, no card, every edition in full.
It becomes $50 a year, and signing up now keeps your first year free.