GPT-6 Astra vs Mistral Large 3

Head-to-head technical comparison of intelligence, capabilities, and API pricing.

GPT-6 Astra
OpenAI
AI Mastery Index96.7
LMSYS Arena1496
Technical (MMLU-Pro)95.8%
Cost per 1M Tokens$10
Mistral Large 3
Mistral
AI Mastery Index89.2
LMSYS Arena1430
Technical (MMLU-Pro)89.2%
Cost per 1M Tokens$0.5

Which should you use?

GPT-6 Astra leads on the composite index by 7.5 points (96.7 vs 89.2).

Cost is the sharper difference: GPT-6 Astra is 20x the input price of Mistral Large 3 ($10 against $0.5 per 1M), so at volume the choice is usually decided by budget rather than benchmarks.

Pick GPT-6 Astra when

  • Higher composite index — 96.7 against 89.2, a gap of 7.5 points.
  • Ahead on Arena Elo by 66 points (1496 vs 1430), which is outside the board's published confidence intervals.
  • Stronger on MMLU-Pro: 95.8% against 89.2%.

Pick Mistral Large 3 when

  • Cheaper input tokens — $0.5 against $10 per 1M, so GPT-6 Astra costs 20x as much to feed.
  • Better value per point of measured capability: $0.006 per index point against $0.103.

Value per point of measured capability, at list input pricing: Mistral Large 3 $0.006 · GPT-6 Astra $0.103 per index point. Run your own token mix through the token cost calculator — a comparison at list price ignores caching and batch discounts, which move real bills more than this gap does.

Our reporting on OpenAI and Mistral