GPT-6 Astra vs Mistral Medium 3.5

GPT-6 Astra vs Mistral Medium 3.5: which AI model is cheaper, has the larger context window and more capabilities? Side-by-side comparison updated daily.

Quick verdict

  • Mistral Medium 3.5 is 6.7× cheaper than GPT-6 Astra for the same mix of input and output tokens.
  • GPT-6 Astra has the larger context window (1.1M), useful for long documents and big codebases.
  • GPT-6 Astra is the more recent release (Sep 4, 2026).
  • GPT-6 Astra scores higher on independent tests (overall index 166.6 vs 141.4).
  • Choose Mistral Medium 3.5 if cost matters most; choose GPT-6 Astra if you need its specific strengths above. For the best results, test both on your own prompts.
GPT-6 AstraMistral Medium 3.5
CompanyOpenAIMistral AI
ReleasedSep 4, 2026 ●Apr 30, 2026
Overall index166.6 ●141.4
GPQA Diamond95.8%—
AIME math100%—
FrontierMath93.7%—
SimpleQA Verified75.6%—
Input (per 1M tokens)$10$1.50 ●
Output (per 1M tokens)$50$7.50 ●
Cost for 1M input + 1M output tokens$60.00$9.00 ●
Providers7 ●3
Context1.1M ●256K
Max output128K210K ●
InputsFiles, Image, TextText, Image, Files
OutputsTextText
Reasoning✓✓
Tool use✓✓
Structured output✓✓
Open weights——

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