Noometry

Model comparison

Claude Opus 4.8 vs Mistral Small 3.1

Claude Opus 4.8 is the stronger model overall, scoring 60.7 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 4.8's lead doesn't matter for your workload.

Last verified . 23 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #13 Confirmed

Mistral Small 3.1 Mistral AI

31.7

Rank #269 Confirmed

Summary

  • They share 23 benchmarks with published results for both. Claude Opus 4.8 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 4.8 leads 78.4 to 14.7.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 98.3% for Claude Opus 4.8 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 4.8.
  • Claude Opus 4.8 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 4.8Mistral Small 3.1
ProviderAnthropicMistral AI
Noometry Index60.731.7
Released2026-05-282025-03-17
WeightsProprietaryOpen
Context window1M128K
Max output128K102K
Input $ / M tokens$5$0.35
Output $ / M tokens$25$0.56
Results tracked6528

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 59.9 (#12), Mistral Small 3.1: 38.3 (#179)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Coding14901309
DeepSWE59%—
FrontierCode46.5%—
LMArena WebDev1556—
SciCode53.5%—
GSO47.1%—
WeirdML82.9%—
ALE-Bench1,564—

Agentic & Tool Use Not comparable

Claude Opus 4.8: 47.6 (#11), Mistral Small 3.1: —

BenchmarkClaude Opus 4.8Mistral Small 3.1
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
LMArena Search1204—
Vending-Bench 25,787—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.7 (#16), Mistral Small 3.1: 19.7 (#254)

BenchmarkClaude Opus 4.8Mistral Small 3.1
Chess Puzzles34%1%
LMArena Hard Prompts14821278
Epoch Capabilities Index158.21127.48
ARC-AGI-272.1%—
SimpleBench64.8%—
Kagi LLM Benchmark88.8%—
NYT Connections (extended)91.1%—
ARC-AGI-192.5%—
CritPt20.9%—
EnigmaEval23.5%—
EBR-Bench28.6%—
Mystery Game Puzzles36%—
DTBench94.9%—
LMCA57.5%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
ForecastBench59.9—

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.4 (#13), Mistral Small 3.1: 14.7 (#301)

BenchmarkClaude Opus 4.8Mistral Small 3.1
OTIS Mock AIME 2024-202598.3%3.9%
LMArena Math14871262
FrontierMath (Tiers 1-3)80%—
FrontierMath Tier 456.1%—
MathArena Final-Answer Competitions91.8%—
ProofBench69%—
Omni-MATH—24.8%
FrontierMath (Feb 2025 set)47.2%—
FrontierMath Tier 4 (v1)31.3%—

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#29), Mistral Small 3.1: 22.6 (#271)

BenchmarkClaude Opus 4.8Mistral Small 3.1
GPQA Diamond91%41.9%
LMArena Expert15021257
SimpleQA Verified53%—
MMLU-Pro—61%
GPQA (HELM)—39.2%

Multimodal Claude Opus 4.8 leads

Claude Opus 4.8: 42.9 (#26), Mistral Small 3.1: 33.2 (#99)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Vision12941136
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Claude Opus 4.8 leads

Claude Opus 4.8: 55.2 (#33), Mistral Small 3.1: 41.2 (#209)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Non-English14501255
LMArena Chinese15071253
LMArena French14811273
LMArena German14721266
LMArena Japanese14401208
LMArena Korean14321206
LMArena Russian14741263
LMArena Spanish14661283

Instruction Following Claude Opus 4.8 leads

Claude Opus 4.8: 77.4 (#24), Mistral Small 3.1: 63.6 (#230)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Instruction Following14761264
IFEval—75%

Long Context Claude Opus 4.8 leads

Claude Opus 4.8: 45.4 (#35), Mistral Small 3.1: 39.5 (#178)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Longer Query14831299

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.0 (#16), Mistral Small 3.1: 37.0 (#259)

BenchmarkClaude Opus 4.8Mistral Small 3.1
LMArena Text14611277
LMArena Creative Writing14541253
EQ-Bench Creative Writing1840761
LMArena Multi-Turn14761270
WildBench—78.8%
EQ-Bench 41281—

Frequently asked questions

Is Claude Opus 4.8 better than Mistral Small 3.1?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 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 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 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 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or Mistral Small 3.1 better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 59.9 versus 38.3 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.8 does, with 1M tokens against 128K.

How many benchmarks do Claude Opus 4.8 and Mistral Small 3.1 share?

23 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and Mistral Small 3.1 has 28.

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