GPT-5.6 Luna

OpenAI is rolling out a ChatGPT-specific tuning of GPT-5.6 Sol that merges Instant and Thinking modes behind a new reasoning slider for Plus and Pro subscribers. Free users now get unlimited text chats with GPT-5.6 Luna and a new Think button.

DeepSeek has updated its budget model V4 Flash to version '0731,' pushing its Artificial Analysis Intelligence Index score to 50 — just one point behind OpenAI's GPT-5.6 Luna — while costing an estimated 60 percent less per task. The MIT-licensed model keeps its 284B-parameter architecture but shows major gains in agentic benchmarks and token efficiency.