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GPT-6 Astra: price, access and benchmarks
GPT-6 Astra is OpenAI's most capable model. It went to paid users on September 4, 2026. It is also the most expensive model we track.
Key facts
| API model ID | gpt-6-astra |
|---|---|
| Released | September 4, 2026 (limited preview a day earlier) |
| Context window | 1.05M tokens |
| Max output | 128K tokens |
| Where | ChatGPT Plus, Pro, Business and Enterprise; OpenAI API; Microsoft Azure; AWS Bedrock |
| Enterprise | Off by default; admins turn it on per workspace |
Source: OpenAI: GPT-6 Astra model page
GPT-6 Astra API pricing
- Standard: $10 per 1M input, $1 cached input, $50 output.
- Long prompts: $20 / $75 above OpenAI's long-context threshold.
- Fast mode costs 2x for about twice the speed. The Batch tier halves the price.
Source: OpenAI API pricing
Coding benchmarks (OpenAI's numbers)
From OpenAI's Astra launch post, against its previous flagship:
| Benchmark | GPT-6 Astra | GPT-5.6 Sol |
|---|---|---|
| Terminal-Bench 4.0 | 57.9% | 37.3% |
| DeepSWE v1.1 | 74.1% | 72.7% |
| FrontierCode 1.1 Extended | 64.5% | 60.6% |
Source: OpenAI: GPT-6 Astra launch
What happened to GPT-6.1 Astra?
- It was not released. Reporting on 2026-09-28 and 29 said OpenAI held it back after safety testing, and shipped GPT-6.1 Sol instead.
- There is no GPT-6.1 Astra model ID or price. GPT-6 Astra remains the one you can use.
Source: Gizmodo on GPT-6.1 Astra
Cost per coding task
List prices with our calculator's assumptions, per agent task:
| Codebase size | GPT-6 Astra | Opus 5.5 | GPT-6.1 Sol |
|---|---|---|---|
| Small (< 10k lines) | $0.576 | $0.223 | $0.112 |
| Medium (10k-100k lines) | $1.290 | $0.498 | $0.249 |
| Large / monorepo (> 100k lines) | $3.090 | $1.188 | $0.594 |
At 173 tasks a month on a medium codebase: about $223 on Astra, $86 on Claude Opus 5.5 and $43 on GPT-6.1 Sol.
Opus 5.5 vs GPT-6 Astra GPT-6 Sol and 6.1 Sol
FAQ
How much does GPT-6 Astra cost?
$10 per 1M input tokens and $50 per 1M output tokens, with cached input at $1. Long prompts cost $20 / $75.
Is GPT-6.1 Astra out?
No. It was reported as held back over safety concerns in late September 2026. OpenAI released GPT-6.1 Sol instead.
Can I use GPT-6 Astra for free?
No. In ChatGPT it needs Plus, Pro, Business or Enterprise; on the API it is billed per token.
Is GPT-6 Astra better than Claude Opus 5.5?
It depends on the benchmark. See our Opus 5.5 vs GPT-6 Astra comparison; Opus 5.5 is also 2.5x cheaper per token.
Independent page. Not affiliated with OpenAI. Benchmarks are OpenAI's own; we have not run our own tests.