High-volume, cost-sensitive work
Choose GPT-6 Astra
GPT-6 Astra costs 43% less on a typical mix of three input tokens for every output token ($20.00 against $35.00 per million tokens).
GPT-6 Astra vs o3-pro: price, context and capabilities
Choose GPT-6 Astra for high-volume, cost-sensitive work, writing and code generation, very long inputs, the latest release and the most recent knowledge; on the other points the two are level or the data is missing.
In short
- GPT-6 Astra is 43% cheaper than o3-pro at the headline price ($20.00 / 1M tokens vs $35.00 / 1M tokens).
- GPT-6 Astra reads more per request: 1.05M tokens against 200k.
- GPT-6 Astra is the newer model (Sep 3, 2026, against Jun 10, 2025).
- Only GPT-6 Astra offers prompt caching.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose GPT-6 Astra
GPT-6 Astra charges $50.00 per million output tokens, against $80.00 for o3-pro. Output dominates the bill when answers are long.
Very long inputs
Choose GPT-6 Astra
GPT-6 Astra reads up to 1.05M tokens per request, against 200k for o3-pro.
Latest release
Choose GPT-6 Astra
GPT-6 Astra is the newer release (Sep 3, 2026, against Jun 10, 2025 for o3-pro).
Most recent knowledge
Choose GPT-6 Astra
GPT-6 Astra was trained on data up to April 2026, against June 2024 for o3-pro.
Monthly cost at three volumes
| Volume | GPT-6 Astra | o3-pro | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $22.50 | $40.00 | GPT-6 Astra, $17.50 less |
| Production: 20M input, 5M output tokens | $450.00 | $800.00 | GPT-6 Astra, $350.00 less |
| Scale: 500M input, 100M output tokens | $10,000 | $18,000 | GPT-6 Astra, $8,000 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| GPT-6 Astra | o3-pro | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Category | Language models | Language models |
| Status | Generally available | Legacy |
| Headline price | $20.00 / 1M tokens | $35.00 / 1M tokens |
| Input | $10.00 / 1M tokens | $20.00 / 1M tokens |
| Output | $50.00 / 1M tokens | $80.00 / 1M tokens |
| Cached input | $1.00 / 1M tokens | No data |
| Context window | 1.05M | 200k |
| Max output | 128k | 100k |
| Released | Sep 3, 2026 | Jun 10, 2025 |
| Knowledge cutoff | April 2026 | June 2024 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Batch API |
| API model id | gpt-6-astra | o3-pro |
Benchmarks side by side
Leader in bold.
| Benchmark | GPT-6 Astra | o3-pro |
|---|---|---|
| GPQA Diamond | 96.1% | 84.5% |
| Intelligence Index | 52.7 | No data |
| SciCode | 56.5% | No data |
| Humanity's Last Exam | 54.7% | No data |
| MMMU-Pro (visual reasoning) | 86.9% | No data |
| Long-context reasoning (AA-LCR) | 80.7% | No data |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose GPT-6 Astra or o3-pro?
Choose GPT-6 Astra for high-volume, cost-sensitive work, writing and code generation, very long inputs, the latest release and the most recent knowledge; on the other points the two are level or the data is missing.
Which is cheaper, GPT-6 Astra or o3-pro?
GPT-6 Astra is 43% cheaper than o3-pro at the headline price ($20.00 / 1M tokens vs $35.00 / 1M tokens).
Which has the larger context window, GPT-6 Astra or o3-pro?
GPT-6 Astra reads more per request: 1.05M tokens against 200k.
What is the difference between GPT-6 Astra and o3-pro?
GPT-6 Astra is made by OpenAI and o3-pro by OpenAI. GPT-6 Astra is 43% cheaper than o3-pro at the headline price ($20.00 / 1M tokens vs $35.00 / 1M tokens). GPT-6 Astra reads more per request: 1.05M tokens against 200k. GPT-6 Astra is the newer model (Sep 3, 2026, against Jun 10, 2025). Only GPT-6 Astra offers prompt caching.
How much do GPT-6 Astra and o3-pro cost per month?
At 20 million input and 5 million output tokens a month, GPT-6 Astra costs $450.00 and o3-pro costs $800.00, at standard rates.
Which is newer, GPT-6 Astra or o3-pro?
GPT-6 Astra was released on Sep 3, 2026 and o3-pro on Jun 10, 2025.