Noometry

Model comparison

Claude Opus 5.5 vs Mistral Small 4

Claude Opus 5.5 has enough public results to be ranked (#3); Mistral Small 4 does not yet, so treat this comparison as directional.

Last verified . 0 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

Mistral Small 4 Mistral AI

30.8

Unranked Sparse

Summary

  • The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 21.9.
  • Mistral Small 4 is cheaper at $0.075 / $0.30 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 262K.
  • Mistral Small 4 has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5.5Mistral Small 4
ProviderAnthropicMistral AI
Noometry Index68.630.8
Released2026-09-22—
WeightsProprietaryOpen
Context window1M262K
Max output128K210K
Input $ / M tokens$4$0.075
Output $ / M tokens$20$0.30
Results tracked441

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Category by category

Coding Not comparable

Claude Opus 5.5: 71.9 (#3), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
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 Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
APEX-Agents73.5%—
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), Mistral Small 4: 21.9

BenchmarkClaude Opus 5.5Mistral Small 4
ARC-AGI-293.3%—
Kagi LLM Benchmark—40.5%
NYT Connections (extended)88.5%—
ARC-AGI-198.5%—
CritPt31.7%—
EBR-Bench71.4%—
LMArena Hard Prompts1535—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—
Epoch Capabilities Index167.33—

Math Not comparable

Claude Opus 5.5: 91.8 (#3), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
FrontierMath (Tiers 1-3)91.2%—
FrontierMath Tier 495%—
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math1506—
FrontierMath Erdős2.9%—

Knowledge Not comparable

Claude Opus 5.5: 66.4 (#10), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
GPQA Diamond90.6%—
SimpleQA Verified72.2%—
LMArena Expert1547—

Multimodal Not comparable

Claude Opus 5.5: 57.8 (#1), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
LMArena Vision1321—
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Not comparable

Claude Opus 5.5: 59.1 (#2), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
LMArena Non-English1507—
LMArena Chinese1588—
LMArena French1514—
LMArena Russian1520—
LMArena Spanish1507—

Instruction Following Not comparable

Claude Opus 5.5: 80.0 (#3), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
LMArena Instruction Following1537—

Long Context Not comparable

Claude Opus 5.5: 47.1 (#19), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
LMArena Longer Query1532—

Writing & Preference Not comparable

Claude Opus 5.5: 78.2 (#3), Mistral Small 4: —

BenchmarkClaude Opus 5.5Mistral Small 4
LMArena Text1515—
LMArena Creative Writing1533—
EQ-Bench Creative Writing2050—
LMArena Multi-Turn1499—

Frequently asked questions

Is Claude Opus 5.5 better than Mistral Small 4?

Claude Opus 5.5 has enough public results to be ranked (#3); Mistral Small 4 does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 5.5 or Mistral Small 4?

Mistral Small 4 is cheaper. It lists at $0.075 per million input tokens and $0.30 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 262K.

How many benchmarks do Claude Opus 5.5 and Mistral Small 4 share?

0 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Mistral Small 4 has 1.

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