GPT-6.1 Sol is OpenAI’s option for complex coding and professional work, while GPT-6 Luna targets focused, high-volume tasks at a much lower token price. For API developers, the choice depends on whether the extra capability is worth the cost for each request.
OpenAI describes Sol as a fit for complex work where you want strong performance at a lower cost than its flagship model. Luna is aimed at scoped tasks and frequent requests where efficiency matters.
GPT-6.1 Sol vs GPT-6 Luna at a glance
| What matters | GPT-6.1 Sol | GPT-6 Luna |
|---|---|---|
| Best fit | Complex coding, computer use and professional work | Focused, repeatable and high-volume tasks |
| API model ID | gpt-6.1-sol |
gpt-6-luna |
| Input price per 1 million tokens | $2 | $0.10 |
| Output price per 1 million tokens | $10 | $0.50 |
| Context window | 1.05 million tokens | 1.05 million tokens |
These are Standard API rates for prompts up to 272,000 input tokens, not ChatGPT subscription prices. Above that threshold, both models charge twice the input rate and 1.5 times the output rate for the entire request. Your bill also depends on token usage, processing tier and any applicable tool charges.
When GPT-6.1 Sol makes more sense
Choose Sol when the task needs more careful reasoning or several steps of work, such as debugging a tricky issue, using a computer tool, or preparing a detailed deliverable. OpenAI positions it close to Astra on demanding work, at a lower model price. That does not mean every answer will be better for your use case, so test it on the prompts your team actually runs.
When GPT-6 Luna is the better fit
Luna is the practical starting point for routine requests that happen often: sorting or summarising content, handling straightforward support questions, or processing many similar inputs. Its token prices are much lower, so it can be a sensible choice when a task is clearly scoped and latency or cost matters.
For a difficult edge case, you can route that request to Sol instead of paying Sol rates for every routine task. A small evaluation on real examples is more useful than choosing from a benchmark headline alone.
Are these ChatGPT models or API models?
The model catalogue and prices above describe API access. ChatGPT shows the models available to your account and plan, and the model names or limits there may differ. Before building around a model, check both the current API catalogue and the model picker in the product you plan to use.
- SourceOpenAI: API pricing
One response to “GPT-6.1 Sol vs GPT-6 Luna: Which Should You Use?”
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