OpenAI has put its higher-tier model GPT-5.6 Sol in ChatGPT Plus and Pro. After making Luna free this morning, it is now giving paying users a more powerful model. Luna for free, Sol for paid: the tiers are now clearly split.
The Day Sol Came to Plus and Pro: What Changed
- Plus ($20) and Pro ($200): GPT-5.6 Sol included, with both instant and deep reasoning strengthened
- Free and Go: Luna as the default model, plus a "Think" button for stronger reasoning
GPT-5.6 Sol: Where Does the Higher Price Show Its Value?
Sol is the higher-tier model in the GPT-5.6 family. If Luna is optimized for "fast, light everyday conversation," Sol is designed for tasks that need complex reasoning. Plus and Pro users can use instant answers and deep reasoning as the situation calls for.
Think Makes the Model Reason Longer Before Answering: When to Use It
Free and Go users can also press the "Think" button on a hard question to get a more deeply reasoned answer. Fast answers are the default, and the model thinks deeply only when needed. Free users now get a taste of "reasoning," a paid feature.
Wide for Free, Deep for Paid: OpenAI's Separation Strategy
1. Expand free to grow users, differentiate paid to earn revenue. Luna holds free users, and Sol nudges them toward paying.
2. The "free vs. paid" line in AI subscriptions is being redrawn. The stronger free gets, the more paid has to compete on "better reasoning" rather than "a better model."
3. In the ARC-AGI retest, Luna kept its performance even after an 80% price cut, which shows this strategy is not about giving up performance for a lower price.
Free, Plus, or Pro: Which Fits Your Work?
For everyday and simple tasks, free Luna is enough. If you need complex code, analysis, or long reasoning, consider Plus or higher, which includes Sol. Free users should start by trying the Think button.
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