Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war
Claude Opus 5.5, GPT-6 Sol, and GPT-6 Luna launched same-day, with GPT-6 models priced at half of GPT-5.6 equivalents.
Anthropic released Claude Opus 5.5, and roughly an hour later OpenAI released GPT-6 Sol and GPT-6 Luna, following the prior day's Grok 4.7 and MiMo v2.6 Flash/Pro launches. Simon Willison notes GPT-6 Sol and Luna are half the price of their GPT-5.6 equivalents, signaling a new price war. He previously favored GPT-5.6 Luna for application building due to its balance of performance and cost.
- Claude Opus 5.5 and GPT-6 Sol/Luna released within an hour of each other
- GPT-6 pricing is half that of GPT-5.6 equivalents
- Launches follow Grok 4.7 and MiMo v2.6 Flash/Pro the previous day
Yesterday was Grok 4.7 ( pelicans ) and MiMo v2.6 Flash/Pro ( more pelicans ). Today Anthropic released Claude Opus 5.5 , and around an hour later OpenAI released GPT-6 Sol and GPT-6 Luna . It's going to take a while to get a good read on all of these new models, but here are my impressions so far. GPT-6 Sol and Luna are half the price of their GPT-5.6 equivalents GPT-5.6 Luna was already my favorite model for building applications against, because it combined excellent performance with being really cheap . Somehow GPT-6 Luna is half the price of that again - and GPT-6 Sol had a similar reduction compared to GPT-5.6 Sol. Here's what the pricing landscape looks like today: Model Input Cached…
This source does not provide full text. Read it at simonwillison.net.