GPT-6.1 Sol vs GPT-6 Astra
GPT-6 Astra costs five times as much as GPT-6.1 Sol per token, $10 input and $50 output per 1M against $2 and $10, with the same 1.05M-token context and 128K-token output limit. Astra has published benchmark scores and GPT-6.1 Sol has none we can cite, so the question is whether Astra's results are worth five times the price.
Price
Our feature session costs $10.80 on GPT-6.1 Sol and $54 on Astra; a long agent day $97.50 against $488. Cached input is $0.10 against $1, a tenth, so with 90% of prompts cached the feature session costs $2.59 against $15.12. Filling the whole window once is $2.10 against $10.50.
Scores
Astra scored 57.9% on Terminal-Bench 4.0 (OpenAI's figure at high effort, as Anthropic quoted it), 53.3% on FrontierCode 1.1 and 57.2% on Humanity's Last Exam with tools. We have nothing to set against them for GPT-6.1 Sol.
For a sense of scale, Anthropic's Opus 5.5 beats Astra on all three at less than half the price: Opus 5.5 against GPT-6 Astra.
Dates
GPT-6 Astra was first listed on the API on 4 September 2026 and GPT-6.1 Sol four weeks later, on 29 September. Both take text and images. The dates are first API listings, not OpenAI's announcement days, so the newer model is not necessarily the stronger one; without a GPT-6.1 Sol score we can't say.
Side by side
| GPT-6.1 Sol | GPT-6 Astra | |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Released | 29 September 2026[1] first API listing | 4 September 2026[2] first API listing |
| Context window | 1.05M tokens[3] | 1.05M tokens[4] |
| Max output | 128K tokens[3] | 128K tokens[4] |
| Input price | $2 per 1M tokens[3] | $10 per 1M tokens[4] |
| Output price | $10 per 1M tokens[3] | $50 per 1M tokens[4] |
| Cached input | $0.10 per 1M tokens[3] | $1 per 1M tokens[4] |
| Long prompts | One price | One price |
| Price change | None announced | None announced |
| Open weights | No[5] Listed as an API model, not in OpenAI's open-weight section. | No[5] Listed as an API model, not in OpenAI's open-weight section. |
| Reads | text, image[3] | text, image[4] |
Benchmarks
None of the benchmarks below has a published score for both models. We only show a score we can cite with its source and date; "Not published" means we found none for that model, not that it scored zero.
| Benchmark | GPT-6.1 Sol | GPT-6 Astra |
|---|---|---|
| Terminal-Bench 4.0Agentic coding tasks in a real terminal. | Not published | 57.9%[6] As reported by OpenAI (high effort), quoted by Anthropic. |
| FrontierCode 1.1 (Main)Hard software engineering tasks. | Not published | 53.3%[6] Quoted by Anthropic. |
| Humanity's Last Exam (with tools)Expert-level questions across many fields, tools allowed. | Not published | 57.2%[6] Quoted by Anthropic. |
What a coding session costs
Our own estimate from the list prices above, for three sessions we define: a coding agent resends the conversation with every call, so prompts are large and grow. "Cached" assumes 90% of prompt tokens are read from the prompt cache and leaves out cache write fees. A long-prompt price applies when a call's prompt is over its threshold. Work out your own mix with the token cost calculator.
| Session | GPT-6.1 Sol | GPT-6.1 Sol cached | GPT-6 Astra | GPT-6 Astra cached |
|---|---|---|---|---|
| Quick fix10 calls of 25K prompt and 1.5K output tokens | $0.65 | $0.22 | $3.25 | $1.23 |
| Feature session60 calls of 80K prompt and 2K output tokens | $10.80 | $2.59 | $54 | $15.12 |
| Long agent day300 calls of 150K prompt and 2.5K output tokens | $97.50 | $20.55 | $488 | $123 |
Value for money and release gap
GPT-6.1 Sol is dated 4 weeks later (25 days; GPT-6.1 Sol: first API listing; GPT-6 Astra: first API listing). Price per point divides our feature-session cost by a published score: lower means more score for the money. It is a rough lens, not a ranking.
| Measure | GPT-6.1 Sol | GPT-6 Astra |
|---|---|---|
| Input tokens per $1 | 500K | 100K |
| Filling the whole context window once | $2.10 | $10.50 |
Questions
How much more does GPT-6 Astra cost than GPT-6.1 Sol?
Five times as much per token: $10 against $2 per 1M input tokens and $50 against $10 per 1M output. Our feature session costs $54 on Astra and $10.80 on GPT-6.1 Sol.
Is GPT-6 Astra better than GPT-6.1 Sol?
We can't compare them on benchmarks: Astra has published scores, such as 57.9% on Terminal-Bench 4.0, and we found none for GPT-6.1 Sol.
Do GPT-6 Astra and GPT-6.1 Sol have the same context window?
Yes, 1.05M tokens each, and both write up to 128K tokens in one reply.
Most compared
Any other two models: pick them in the lists at the top of the page.
- Claude Opus 5.5 vs GPT-6.1 Sol
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Claude Fable 5.1 vs GPT-6 Astra
- Claude Opus 5.5 vs GPT-6 Astra
- GPT-6.1 Sol vs GPT-6 Sol
- Gemini 4 Argon vs GPT-6.1 Sol
- Claude Opus 5.5 vs Claude Sonnet 5.5
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Opus 5 vs Claude Opus 5.5
- Claude Sonnet 5 vs Claude Sonnet 5.5
- Claude Haiku 5.5 vs Claude Sonnet 5.5
- Claude Haiku 4.5 vs Claude Haiku 5.5
- Claude Fable 5 vs Claude Fable 5.1
- Claude Opus 5.5 vs GPT-5.6 Sol
- Claude Haiku 5.5 vs GPT-6 Luna
- Claude Opus 5.5 vs Gemini 4 Argon
- Claude Sonnet 5.5 vs Gemini 4 Argon
- Claude Opus 5.5 vs Gemini 3.1 Pro Preview
- Gemini 3.1 Pro Preview vs Gemini 4 Argon
- Claude Haiku 5.5 vs Gemini 3.8 Flash
- Claude Opus 5.5 vs Grok 4.7
- Claude Opus 5.5 vs DeepSeek V4 Pro
- Claude Sonnet 5.5 vs Kimi K3
- Claude Sonnet 5.5 vs GLM-5.3
More tools
Sources
Numbers from the makers' own pages, checked by hand, last read . List prices in US dollars before tax. Spotted a mistake? office@shuriken.sh.
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