Noometry

Model comparison

Claude Opus 4.5 vs Devstral Small 2505

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 34.3 on the Noometry Index. Devstral Small 2505 costs 67× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Last verified . 2 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

Devstral Small 2505 Mistral AI

34.3

Rank #233 Reported

Summary

  • They share 2 benchmarks with published results for both. Claude Opus 4.5 scores higher in 2 categories and Devstral Small 2505 in 0 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 4.5 leads 42.6 to 19.7.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 80.2% for Claude Opus 4.5 and 37.7% for Devstral Small 2505.
  • Devstral Small 2505 is cheaper at $0.10 / $0.30 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • Claude Opus 4.5 accepts more context: 200K tokens versus 128K.
  • Devstral Small 2505 has downloadable open weights; the other is API-only.

Side by side

Claude Opus 4.5Devstral Small 2505
ProviderAnthropicMistral AI
Noometry Index50.534.3
Released2025-11-012025-05-07
WeightsProprietaryOpen
Context window200K128K
Max output64K128K
Input $ / M tokens$5$0.10
Output $ / M tokens$25$0.30
Results tracked694

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Category by category

Coding Claude Opus 4.5 leads

Claude Opus 4.5: 54.8 (#27), Devstral Small 2505: 38.9 (#166)

BenchmarkClaude Opus 4.5Devstral Small 2505
SWE-bench Verified (bash only)76.8%56.4%
SWE-bench Verified76.7%—
LMArena WebDev1494—
SWE-bench Multilingual70.7%—
SciCode—28.8%
GSO26.5%—
WeirdML63.7%—
LMArena Coding1504—
ALE-Bench1,025—
AlgoTune1.77—

Agentic & Tool Use Not comparable

Claude Opus 4.5: 47.3 (#12), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
Terminal-Bench63.1%—
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
BALROG43.5%—
LMArena Search1180—
METR Time Horizons75%—
Vending-Bench 24,967—

Reasoning Claude Opus 4.5 leads

Claude Opus 4.5: 42.6 (#51), Devstral Small 2505: 19.7 (#252)

BenchmarkClaude Opus 4.5Devstral Small 2505
Kagi LLM Benchmark80.2%37.7%
ARC-AGI-237.6%—
SimpleBench62%—
NYT Connections (extended)52.5%—
ARC-AGI-180%—
CritPt—0%
Chess Puzzles12%—
EnigmaEval11.9%—
EBR-Bench14.3%—
LMArena Hard Prompts1476—
Mystery Game Puzzles22%—
DTBench89.9%—
LMCA44.5%—
Epoch Capabilities Index150.09—
ForecastBench60.7—

Math Not comparable

Claude Opus 4.5: 38.6 (#132), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
FrontierMath (Tiers 1-3)34.4%—
FrontierMath Tier 44.9%—
OTIS Mock AIME 2024-202586.1%—
ProofBench36%—
LMArena Math1463—
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Not comparable

Claude Opus 4.5: 56.5 (#44), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
GPQA Diamond86%—
Humanity's Last Exam25.2%—
SimpleQA Verified45.7%—
Vectara Hallucination Rate10.9%—
LMArena Expert1487—

Multimodal Not comparable

Claude Opus 4.5: 31.4 (#107), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
GeoBench75%—
VPCT40%—
Furniture Assembly28.3%—
LMArena Document1462—

Multilingual Not comparable

Claude Opus 4.5: 54.3 (#47), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
LMArena Non-English1438—
LMArena Chinese1470—
LMArena French1471—
LMArena German1449—
LMArena Japanese1416—
LMArena Korean1424—
LMArena Russian1447—
LMArena Spanish1458—

Instruction Following Not comparable

Claude Opus 4.5: 77.5 (#19), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
LMArena Instruction Following1478—

Long Context Not comparable

Claude Opus 4.5: 46.5 (#22), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
CL-bench21.1%—
LMArena Longer Query1480—

Writing & Preference Not comparable

Claude Opus 4.5: 68.1 (#28), Devstral Small 2505: —

BenchmarkClaude Opus 4.5Devstral Small 2505
LMArena Text1451—
LMArena Creative Writing1445—
EQ-Bench Creative Writing1687—
LMArena Multi-Turn1466—

Frequently asked questions

Is Claude Opus 4.5 better than Devstral Small 2505?

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 34.3 on the Noometry Index. Devstral Small 2505 costs 67× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.5 or Devstral Small 2505?

Devstral Small 2505 is cheaper. It lists at $0.10 per million input tokens and $0.30 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or Devstral Small 2505 better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 38.9 in the Noometry coding category.

Which has the bigger context window?

Claude Opus 4.5 does, with 200K tokens against 128K.

How many benchmarks do Claude Opus 4.5 and Devstral Small 2505 share?

2 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Devstral Small 2505 has 4.

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