GPT-6.1 Sol vs Claude Sonnet 5.5: a buying guide
A point-by-point comparison of GPT-6.1 Sol and Claude Sonnet 5.5 covering positioning, price, ranking and use cases, noting Astra remains the first choice for hard tasks.
‣ you only need one of the two models that was released yesterday 1 → GPT-6.1 Sol - what OpenAI said it’s for everyday coding, agents, computer use, professional work. - price vs last Sol same list price : $2 / $10. cached input cut in half: $0.20 → $0.10. so agents that reuse context get cheaper. - better than the last Sol? yes. it is smarter than GPT-6 - rank in its field best cheap coder in OpenAI’s stack right now, almost as good as Astra but 1/5 the price of Astra’s token price. - worth switching from GPT-6 Sol? yes. same bill, fewer mistakes and better coding. - when to skip it deep research or “get this right first time” one-shots. use Opus 5.5 or Astra for those. - models still above it Claude Opus 5.5 and Sonnet 5.5, GPT-6 Astra and Claude Fable 5.1 2 → Claude Sonnet 5.5 - what Anthropic said it’s for everyday coding, bugfixes, docs, slides, spreadsheets. Fable-ish quality and faster than Sonnet 5. - price vs last Sonnet same list price: $2 / $10. Anthropic says it uses fewer tokens so tasks cost up to 30% less. - better than last Sonnet? yes. much better - rank in its field number 2 on the independent intelligence board. same seat price as GPT-6.1 Sol. default daily driver if you live in Claude. - worth switching from Sonnet 5? yes. same price, way better coding and knowledge work there's no reason to stay on 5. - when to skip it for simple tasks you need to run at high volume, Luna is still the cheapest option. for the hardest tasks that require long-running agents and deep reasoning, use Opus 5.5. but if maximum reasoning makes the task too expensive, lower the effort level or switch to Sol. Sol costs the same $2/$10 as Sonnet but uses fewer tokens per task - models still above it Claude Opus 5.5, Claude Fable 5.1 and GPT-6 Astra