Claude Opus 4.8 vs Mistral Large 3

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

Claude Opus 4.8
Anthropic
AI Mastery Index94.6
LMSYS Arena1463
Technical (MMLU-Pro)94.5%
Cost per 1M Tokens$5
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?

Claude Opus 4.8 leads on the composite index by 5.4 points (94.6 vs 89.2).

Cost is the sharper difference: Claude Opus 4.8 is 10x the input price of Mistral Large 3 ($5 against $0.5 per 1M), so at volume the choice is usually decided by budget rather than benchmarks.

Pick Claude Opus 4.8 when

  • Higher composite index — 94.6 against 89.2, a gap of 5.4 points.
  • Ahead on Arena Elo by 33 points (1463 vs 1430), which is outside the board's published confidence intervals.
  • Stronger on MMLU-Pro: 94.5% against 89.2%.

Pick Mistral Large 3 when

  • Cheaper input tokens — $0.5 against $5 per 1M, so Claude Opus 4.8 costs 10x as much to feed.
  • Better value per point of measured capability: $0.006 per index point against $0.053.

Value per point of measured capability, at list input pricing: Mistral Large 3 $0.006 · Claude Opus 4.8 $0.053 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 Anthropic and Mistral