GPT-6 Astra — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Developer | OpenAI |
|---|---|
| Type | Reasoning / agentic |
| Modality | Text, vision |
| Parameters | Undisclosed |
| Context window | 1.05M |
| Max output | 128K |
| License | Proprietary |
| Open weights | No |
| Released | 2026-09 |
| Input price | $10.00 /1M |
| Output price | $50.00 /1M |
| API providers | OpenAI API, Microsoft Azure, AWS Bedrock |
Benchmarks
| Artificial Analysis Intelligence Index v4.1.1 | 61.2; GPQA Diamond 96.0%; ARC-AGI-2 95.0%; Terminal-Bench 4.0 57.9%; FrontierMath Tier 4 97.6% |
|---|
GPT-6 Astra is OpenAI’s flagship model announced on 3 September 2026. In the API it is gpt-6-astra: $10 per 1M input tokens, $1 per 1M cached input, $50 per 1M output, a 1,050,000-token context window and 128,000 max output tokens; prompts above 272K input tokens are billed at 2x input/cache and 1.5x output rates, and Fast mode costs 2x for up to 2x speed. Knowledge cutoff 30 April 2026. OpenAI classifies it at the Critical threshold for cybersecurity under its Preparedness Framework, so the launch version refuses advanced offensive tasks such as writing proof-of-concept exploits. Source: OpenAI model page.
GPT-6 Astra pricing: API cost per 1M tokens
| Input (per 1M tokens) | $10.00 |
|---|---|
| Output (per 1M tokens) | $50.00 |
| Output/input ratio | 5× |
| Blended (4:1 in:out) | $18.00 per 1M tokens |
What GPT-6 Astra costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Workload | Tokens / month | Cost / month |
|---|---|---|
| Side project | 1M in / 0.25M out | $23 |
| Small team | 20M in / 5M out | $450 |
| Production | 200M in / 50M out | $4,500 |
Run your own numbers in the AI API cost calculator.
Cheaper alternatives to GPT-6 Astra
| Model | Blended $/1M | You save |
|---|---|---|
| Claude Opus 5 | $9.00 | 50% cheaper |
| GPT-5.6 Sol | $10.00 | 44% cheaper |
| Kimi K3 open | $5.40 | 70% cheaper |
Frequently asked questions
How much does GPT-6 Astra cost per 1M tokens?
GPT-6 Astra costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $18.00 per 1M tokens.
How much does GPT-6 Astra cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $450 on GPT-6 Astra. A side project (1M in / 0.25M out) costs roughly $22.50.
What is a cheaper alternative to GPT-6 Astra?
Claude Opus 5 is the strongest cheaper option in our database at $9.00 per 1M blended — about 50% less than GPT-6 Astra.
Can I run GPT-6 Astra locally?
No. GPT-6 Astra is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does GPT-6 Astra charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. GPT-6 Astra charges 5× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the AI models database or the LLM leaderboard.