Noometry

Model comparison

Claude Opus 5.5 vs Mistral Medium 3

Claude Opus 5.5 has enough public results to be ranked (#3); Mistral Medium 3 does not yet, so treat this comparison as directional.

Last verified . 1 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

Mistral Medium 3 Mistral AI

37.0

Unranked Sparse

Summary

  • They share 1 benchmark with published results for both. Claude Opus 5.5 scores higher in 1 category and Mistral Medium 3 in 0 categories; one gap is clear of the uncertainty.
  • The widest gap is in knowledge, where Claude Opus 5.5 leads 66.4 to 34.6.
  • Mistral Medium 3 is cheaper at $0.40 / $2 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 131K.

Side by side

Claude Opus 5.5Mistral Medium 3
ProviderAnthropicMistral AI
Noometry Index68.637.0
Released2026-09-222025-05-07
WeightsProprietaryProprietary
Context window1M131K
Max output128K131K
Input $ / M tokens$4$0.40
Output $ / M tokens$20$2
Results tracked442

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Category by category

Coding Not comparable

Claude Opus 5.5: 71.9 (#3), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
FrontierCode54.6%—
CursorBench57.8%—
LMArena WebDev1813—
FrontierSWE62.3%—
SciCode66.9%—
LMArena Coding1547—
MirrorCode77.4%—
ALE-Bench2,147—

Agentic & Tool Use Not comparable

Claude Opus 5.5: 45.3 (#15), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
APEX-Agents73.5%—
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Not comparable

Claude Opus 5.5: 80.2 (#3), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
Epoch Capabilities Index167.33134.07
ARC-AGI-293.3%—
NYT Connections (extended)88.5%—
ARC-AGI-198.5%—
CritPt31.7%—
EBR-Bench71.4%—
LMArena Hard Prompts1535—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—

Math Not comparable

Claude Opus 5.5: 91.8 (#3), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math1506—
FrontierMath Erdős2.9%—

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.4 (#10), Mistral Medium 3: 34.6

BenchmarkClaude Opus 5.5Mistral Medium 3
GPQA Diamond90.6%—
SimpleQA Verified72.2%—
Confabulations—21.9%
LMArena Expert1547—

Multimodal Not comparable

Claude Opus 5.5: 57.8 (#1), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
LMArena Vision1321—
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Not comparable

Claude Opus 5.5: 59.1 (#2), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
LMArena Non-English1507—
LMArena Chinese1588—
LMArena French1514—
LMArena Russian1520—
LMArena Spanish1507—

Instruction Following Not comparable

Claude Opus 5.5: 80.0 (#3), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
LMArena Instruction Following1537—

Long Context Not comparable

Claude Opus 5.5: 47.1 (#19), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
LMArena Longer Query1532—

Writing & Preference Not comparable

Claude Opus 5.5: 78.2 (#3), Mistral Medium 3: —

BenchmarkClaude Opus 5.5Mistral Medium 3
LMArena Text1515—
LMArena Creative Writing1533—
EQ-Bench Creative Writing2050—
LMArena Multi-Turn1499—

Frequently asked questions

Is Claude Opus 5.5 better than Mistral Medium 3?

Claude Opus 5.5 has enough public results to be ranked (#3); Mistral Medium 3 does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 5.5 or Mistral Medium 3?

Mistral Medium 3 is cheaper. It lists at $0.40 per million input tokens and $2 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 131K.

How many benchmarks do Claude Opus 5.5 and Mistral Medium 3 share?

1 benchmark has published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Mistral Medium 3 has 2.

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