Modelpeers
GPT-6 Luna character

ChatGPT, GPT-6 Sol and GPT-6 Luna

3 products from OpenAI

Default change

GPT-6 becomes the ChatGPT model on free and paid plans

OpenAI launched GPT-6 to everyone in ChatGPT on free and paid plans globally, replacing GPT-5.6 Sol and GPT-5.6 Luna in ChatGPT. Codex and ChatGPT Work keep the September versions.

Before

GPT-5.6 Sol and GPT-5.6 Luna

After

GPT-6 Sol and GPT-6 Luna

Who is affected:
Everyone using ChatGPT.
What to do:
No action needed. re-check saved prompts and GPTs for changed behavior.

Source

"These models will replace GPT-5.6 Sol and GPT-5.6 Luna in ChatGPT."

OpenAI Deployment Safety Hub, GPT-6 Sol and GPT-6 Luna October 2026 update

Published

Open the sourcedeploymentsafety.openai.com

Modelpeers tracks changes to AI agents and models, each from its source. Follow ChatGPT to get a weekly email when it changes.