ChatGPT's free tier goes unlimited on GPT-5.6 Luna this week
The bigger signal for builders sits underneath: Luna's API price fell 80%, Sol becomes OpenAI's production pick, and Plus gains a reasoning slider.
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Luna is the new free default, and text chats are uncapped
GPT-5.6 Luna replaces GPT-5.5 Instant for Free and Go users, with unlimited text conversations and a new Think button for harder questions rolling out the week of Aug 10. Caps stay on images, files, voice, and image generation, and OpenAI says Luna makes 62% fewer factual errors than the model it replaces.
The builder angle: Luna is 80% cheaper on the API
It is the same model you can call directly, and OpenAI cut Luna's API price about 80% on July 30, to $1.20 per million output tokens from $6.00. The workhorse now serving hundreds of millions of free-tier chats is also the cheapest capable model in the GPT-5.6 line.
Plus and Pro move to Sol, with a thinking slider
Paid tiers get GPT-5.6 Sol, now OpenAI's recommended model for production API use, plus a slider to dial reasoning effort up or down per query. Fast mode runs Sol, Terra, and Luna up to 2.5x faster once a request passes 272K tokens.
Elsewhere: Gemini Omni Flash puts video generation in the API
Google's Omni Flash generates and edits clips from text, image, video, or audio references, live in the Gemini app and on the API from roughly $0.11 a second. If you have wanted to add a video feature without stitching together a separate pipeline, this is the weekend unlock.