Claude Opus 5 vs Mistral Large 3
Head-to-head technical comparison of intelligence, capabilities, and API pricing.
Which should you use?
Claude Opus 5 leads on the composite index by 7.4 points (96.6 vs 89.2).
Cost is the sharper difference: Claude Opus 5 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 5 when
- Higher composite index — 96.6 against 89.2, a gap of 7.4 points.
- Ahead on Arena Elo by 63 points (1493 vs 1430), which is outside the board's published confidence intervals.
- Stronger on MMLU-Pro: 95.7% against 89.2%.
Pick Mistral Large 3 when
- Cheaper input tokens — $0.5 against $5 per 1M, so Claude Opus 5 costs 10x as much to feed.
- Better value per point of measured capability: $0.006 per index point against $0.052.
Value per point of measured capability, at list input pricing: Mistral Large 3 $0.006 · Claude Opus 5 $0.052 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.
Where these numbers come from
Figures as of 2026-09-07. Arena Elo and pricing are read from the public board and each vendor's own pricing page; see the full leaderboard for all 34 models and which columns are measured rather than estimated, or the benchmark matrix for scores benchmark by benchmark.