GPT-5.1 High vs GPT-6 Astra: Specs & Benchmark Comparison
GPT-5.1 High and GPT-6 Astra both come from OpenAI, GPT-5.1 High was released in November 2025, and GPT-6 Astra followed 10 months later in September 2026.
We have 3 benchmark results for GPT-5.1 High and 22 benchmark results for GPT-6 Astra, but they overlap on a single test: GPQA, where GPT-6 Astra scores 96.0% against 88.0%.
GPT-5.1 High is the cheaper API at $1.25 per million input tokens and $10 per million output tokens, roughly 8 times cheaper than GPT-6 Astra at $10 and $50. GPT-6 Astra takes the larger context window at 1M tokens, compared with 400K for GPT-5.1 High. Both accept text and images as input.
| Characteristic | GPT-5.1 High | GPT-6 Astra |
|---|---|---|
| Company | OpenAI | OpenAI |
| Release Date | November 11, 2025 | September 4, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 400K | 1.1M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $1.25 | $10.00 |
| Output Price / 1M | $10.00 | $50.00 |
| Average Score | 86.7% | 74.4% |
| Benchmarks | ||
| GPQA | 88.0% | 96.0% |
Visual Benchmark Comparison
Verdict
GPT-6 Astra leads in 2 out of 4 comparison categories.
Both models show comparable average scores: GPT-5.1 High — 0.9, GPT-6 Astra — 0.7.
GPT-5.1 High is 5.3x cheaper: input $1.25/1M vs $10.00/1M tokens.
GPT-6 Astra supports a larger context: 1M vs 400K tokens.
GPT-6 Astra is newer: released 9/4/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — GPT-5.1 High or GPT-6 Astra?
Which model is cheaper — GPT-5.1 High or GPT-6 Astra?
Which has a larger context window — GPT-5.1 High or GPT-6 Astra?
The GPT-5.1 High and GPT-6 Astra comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.1 High or GPT-6 Astra page. See also the complete list of AI model comparisons.