Noometry

Model comparison

Claude Opus 4.6 vs Mistral Small 3.1

Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 25× less per token, which makes it the better buy when Claude Opus 4.6's lead doesn't matter for your workload.

Last verified . 23 shared benchmarks.

Claude Opus 4.6 Anthropic

58.2

Rank #20 Confirmed

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

Summary

  • They share 23 benchmarks with published results for both. Claude Opus 4.6 scores higher in 9 categories and Mistral Small 3.1 in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.6 leads 63.0 to 14.7.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 94.4% for Claude Opus 4.6 and 3.9% for Mistral Small 3.1.
  • Mistral Small 3.1 is cheaper at $0.35 / $0.56 per million input/output tokens, against $5 / $25 for Claude Opus 4.6.
  • Claude Opus 4.6 accepts more context: 1M tokens versus 128K.
  • Mistral Small 3.1 has downloadable open weights; the other is API-only.

Side by side

Claude Opus 4.6Mistral Small 3.1
ProviderAnthropicMistral AI
Noometry Index58.231.7
Released2026-02-042025-03-17
WeightsProprietaryOpen
Context window1M128K
Max output128K102K
Input $ / M tokens$5$0.35
Output $ / M tokens$25$0.56
Results tracked6828

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Claude Opus 4.6 leads

Claude Opus 4.6: 57.2 (#20), Mistral Small 3.1: 38.3 (#179)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Coding15361309
SWE-bench Verified78.7%—
FrontierCode26.6%—
SWE-bench Verified (bash only)75.6%—
LMArena WebDev1547—
SWE-bench Multilingual72%—
GSO41.2%—
WeirdML78%—
ALE-Bench996.5—
AlgoTune1.47—

Agentic & Tool Use Not comparable

Claude Opus 4.6: 51.1 (#4), Mistral Small 3.1: —

BenchmarkClaude Opus 4.6Mistral Small 3.1
Terminal-Bench79.8%—
APEX-Agents46.3%—
Remote Labor Index4.2%—
τ²-bench Banking27.3%—
Cybench93%—
DeepResearch Bench55.3%—
GBAEval44.1%—
LMArena Search1253—
METR Time Horizons78.9%—
Vending-Bench 28,018—

Reasoning Claude Opus 4.6 leads

Claude Opus 4.6: 57.8 (#23), Mistral Small 3.1: 19.7 (#254)

BenchmarkClaude Opus 4.6Mistral Small 3.1
Chess Puzzles17%1%
LMArena Hard Prompts15271278
Epoch Capabilities Index155.24127.48
ARC-AGI-269.2%—
SimpleBench67.6%—
Kagi LLM Benchmark83.6%—
NYT Connections (extended)92.1%—
ARC-AGI-194%—
EnigmaEval7.6%—
Thematic Generalization80.6%—
EBR-Bench12.7%—
Mystery Game Puzzles25%—
DTBench91.2%—
LMCA55.8%—
ForecastBench60—

Math Claude Opus 4.6 leads

Claude Opus 4.6: 63.0 (#31), Mistral Small 3.1: 14.7 (#301)

BenchmarkClaude Opus 4.6Mistral Small 3.1
OTIS Mock AIME 2024-202594.4%3.9%
LMArena Math15191262
FrontierMath (Tiers 1-3)66%—
FrontierMath Tier 426.8%—
MathArena Final-Answer Competitions78.5%—
ProofBench50%—
Omni-MATH—24.8%
FrontierMath (Feb 2025 set)40.7%—
FrontierMath Tier 4 (v1)22.9%—

Knowledge Claude Opus 4.6 leads

Claude Opus 4.6: 61.9 (#26), Mistral Small 3.1: 22.6 (#271)

BenchmarkClaude Opus 4.6Mistral Small 3.1
GPQA Diamond90.5%41.9%
LMArena Expert15461257
Humanity's Last Exam34.4%—
SimpleQA Verified47%—
MMLU-Pro—61%
Vectara Hallucination Rate12.2%—
GPQA (HELM)—39.2%

Multimodal Claude Opus 4.6 leads

Claude Opus 4.6: 37.3 (#74), Mistral Small 3.1: 33.2 (#99)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Vision13161136
Furniture Assembly28.3%—
LMArena Document1507—

Multilingual Claude Opus 4.6 leads

Claude Opus 4.6: 57.9 (#6), Mistral Small 3.1: 41.2 (#209)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Non-English14891255
LMArena Chinese15511253
LMArena French15131273
LMArena German15021266
LMArena Japanese14841208
LMArena Korean14641206
LMArena Russian14971263
LMArena Spanish15101283

Instruction Following Claude Opus 4.6 leads

Claude Opus 4.6: 79.5 (#4), Mistral Small 3.1: 63.6 (#230)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Instruction Following15231264
IFEval—75%

Long Context Claude Opus 4.6 leads

Claude Opus 4.6: 48.1 (#13), Mistral Small 3.1: 39.5 (#178)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Longer Query15201299
CL-bench20.7%—
CL-bench Life17%—

Writing & Preference Claude Opus 4.6 leads

Claude Opus 4.6: 73.5 (#10), Mistral Small 3.1: 37.0 (#259)

BenchmarkClaude Opus 4.6Mistral Small 3.1
LMArena Text15031277
LMArena Creative Writing15051253
EQ-Bench Creative Writing1809761
LMArena Multi-Turn15131270
WildBench—78.8%
EQ-Bench 41223—

Frequently asked questions

Is Claude Opus 4.6 better than Mistral Small 3.1?

Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 31.7 on the Noometry Index. Mistral Small 3.1 costs 25× less per token, which makes it the better buy when Claude Opus 4.6's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.6 or Mistral Small 3.1?

Mistral Small 3.1 is cheaper. It lists at $0.35 per million input tokens and $0.56 per million output tokens; Claude Opus 4.6 lists at $5 and $25.

Is Claude Opus 4.6 or Mistral Small 3.1 better for coding?

Claude Opus 4.6 scores higher on coding benchmarks: 57.2 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.6 does, with 1M tokens against 128K.

How many benchmarks do Claude Opus 4.6 and Mistral Small 3.1 share?

23 benchmarks have published results for both models. Claude Opus 4.6 has 68 scored results on Noometry and Mistral Small 3.1 has 28.

Related comparisons

Go deeper