GPT-5.1 Medium vs GPT-6 Astra: Specs & Benchmark Comparison

CharacteristicGPT-5.1 MediumGPT-6 Astra
CompanyOpenAIOpenAI
Release DateNovember 11, 2025September 3, 2026
Parameters
MultimodalYesYes
Context (input)256K1.1M
Context (output)64K128K
Input Price / 1M$1.00$10.00
Output Price / 1M$4.00$50.00
Average Score1.00.7

Verdict

GPT-6 Astra leads in 2 out of 4 comparison categories.

Overall Performance

Both models show comparable average scores: GPT-5.1 Medium — 1.0, GPT-6 Astra — 0.7.

API Cost

GPT-5.1 Medium is 12.0x cheaper: input $1.00/1M vs $10.00/1M tokens.

Context Window

GPT-6 Astra supports a larger context: 1M vs 256K tokens.

Recency

GPT-6 Astra is newer: released 9/3/2026 vs 11/11/2025.

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Frequently Asked Questions

Which is better for coding — GPT-5.1 Medium or GPT-6 Astra?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GPT-5.1 Medium or GPT-6 Astra?
GPT-5.1 Medium is cheaper for input: $1.00 per 1M tokens vs $10.00.
Which has a larger context window — GPT-5.1 Medium or GPT-6 Astra?
GPT-6 Astra supports a larger context: 1,050,000 tokens vs 256,000.

The GPT-5.1 Medium 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 Medium or GPT-6 Astra page. See also the complete list of AI model comparisons.