The BriefOpenAI made its newest models, called GPT-5.6, available to everyone on July 9. There are three versions, named Sol, Terra, and Luna, running from the most powerful and expensive down to the fastest and cheapest, and the middle one now does roughly what last year's top model did for about half the price. It matters because the cost of capable AI keeps dropping fast, and it landed the same week SpaceXAI shipped a rival coding model, Grok 4.5, at even lower prices, so the tools people lean on at work are getting better and cheaper at the same time.
Level UpTwo flagship models shipped a day apart this week, and both claim to beat the other on carefully chosen benchmarks. The skill worth building is running your own quick test instead of trusting the launch charts: pull five real tasks from your own work, run them through two models side by side, and judge the results yourself. Simon Willison's hands-on writeup of GPT-5.6 is a good example of what a grounded, do-it-yourself comparison looks like. The new GPT-5.6 family: Luna, Terra, Sol (Simon Willison)
| 1. Claude Fable 5 (High) |
| 2. Claude Opus 4.8 (Thinking) |
| 3. GPT 5.5 (xHigh) |
| 4. Claude Opus 4.7 (Thinking) |
| 5. Claude Opus 4.7 |