Home / GPT-6.1 Sol vs GPT-6 Astra
GPT-6.1 Sol vs GPT-6 Astra
GPT-6 Astra is OpenAI’s most capable model and costs five times as much as GPT-6.1 Sol. OpenAI describes Sol as near-Astra performance at a lower cost. Both have the same context and output limits.
Checked October 13, 2026 against OpenAI’s model pages and pricing page
| GPT-6 Astra | GPT-6.1 Sol | |
|---|---|---|
| What OpenAI says it is for | The most demanding work: complex reasoning, coding, computer use, research and document creation | Complex coding, computer use and professional work, at near-Astra performance for a lower cost |
| Input, per 1M tokens | $10.00 | $2.00 |
| Cached input | $1.00 | $0.10 |
| Cache write | $12.50 | $2.50 |
| Output | $50.00 | $10.00 |
| Prompts over 272,000 tokens | $20.00 in, $75.00 out | $4.00 in, $15.00 out |
| Batch and Flex | $5.00 / $25.00 | $1.00 / $5.00 |
| Ultrafast | $60 / $300 | $12 / $60 |
| Context window | 1,050,000 tokens (up to 922,000 in) | 1,050,000 tokens (up to 922,000 in) |
| Max output | 128,000 tokens | 128,000 tokens |
| Knowledge cutoff | 30 April 2026 | 30 April 2026 |
| Reasoning effort settings | low, medium, high, xhigh, max | low, medium (default), high, xhigh, max |
| Input / output types | Text and image in, text out | Text and image in, text out |
What OpenAI recommends
OpenAI’s models page says to start with GPT-6 Astra for complex reasoning and coding, to choose GPT-6.1 Sol to balance intelligence and cost, and GPT-6 Luna for cost-sensitive, high-volume work. On the GPT-6.1 Sol page, OpenAI suggests comparing Sol with Astra on your own tasks to judge the trade-off between quality and cost.
The price side of that trade-off is fixed: Astra costs five times as much for input and output, and ten times as much for cached input ($1.00 against $0.10). Caching therefore saves more on Sol. This page compares prices and published specs only.
GPT-6.1 Sol or GPT-6 Sol?
OpenAI still lists the earlier GPT-6 Sol at the same input and output price as GPT-6.1 Sol ($2.00 and $10.00), but its cached input costs twice as much: $0.20 against $0.10.
What the difference costs in a month
Astra vs Sol for your use
Models
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