Model comparison

Claude Sonnet 4.5 vs Molmo 2 8b

Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 39.1 on the Noometry Index.

Last verified . 4 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.1

Rank #81 Confirmed

Summary

  • They share 4 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 5 categories and Molmo 2 8b in 0 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where Claude Sonnet 4.5 leads 66.5 to 49.4.
  • Molmo 2 8b has downloadable open weights; the other is API-only.

Side by side

Claude Sonnet 4.5 and Molmo 2 8b specifications
Claude Sonnet 4.5Molmo 2 8b
ProviderAnthropicAllen Institute for AI (Ai2)
Noometry Index44.139.1
Released2025-09-29—
WeightsProprietaryOpen
Context window200K—
Max output64K—
Input $ / M tokens$3—
Output $ / M tokens$15—
Results tracked735

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Category by category

Coding Not comparable

Claude Sonnet 4.5: 47.3 (#61), Molmo 2 8b: —

Coding benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
SWE-bench Verified71.3%—
SWE-bench Verified (bash only)71.4%—
LMArena WebDev1393—
SWE-bench Multilingual67%—
SciCode44.7%—
GSO14.7%—
WeirdML47.7%—
LMArena Coding1489—
ALE-Bench796.15—
AlgoTune1.52—

Agentic & Tool Use Not comparable

Claude Sonnet 4.5: 38.3 (#32), Molmo 2 8b: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
Terminal-Bench46.5%—
Berkeley Function Calling Leaderboard73.2%—
GDPval42.5%—
Remote Labor Index2.1%—
τ²-bench Airline72%—
τ²-bench Banking25.3%—
τ²-bench Retail72.4%—
τ²-bench Telecom84.9%—
Cybench60%—
DeepResearch Bench52.6%—
OSWorld62.9%—
LMArena Search1159—
METR Time Horizons67.4%—
Vending-Bench 23,839—

Reasoning Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 26.9 (#125), Molmo 2 8b: 25.6 (#146)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Hard Prompts14621287
ARC-AGI-213.6%—
SimpleBench54.3%—
Kagi LLM Benchmark57.9%—
NYT Connections (extended)37.3%—
ARC-AGI-163.7%—
CritPt1.1%—
Chess Puzzles12%—
EnigmaEval6%—
EBR-Bench2.4%—
Mystery Game Puzzles17%—
DTBench83.2%—
LMCA38.8%—
Epoch Capabilities Index146.84—
ForecastBench61.9—

Math Not comparable

Claude Sonnet 4.5: 32.3 (#216), Molmo 2 8b: —

Math benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
FrontierMath (Tiers 1-3)23.9%—
FrontierMath Tier 42.4%—
OTIS Mock AIME 2024-202577.8%—
ProofBench19%—
Omni-MATH55.3%—
LMArena Math1449—
MATH Level 597.7%—
FrontierMath (Feb 2025 set)15.2%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Not comparable

Claude Sonnet 4.5: 48.4 (#76), Molmo 2 8b: —

Knowledge benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
GPQA Diamond82.3%—
Humanity's Last Exam13.7%—
SimpleQA Verified30.7%—
MMLU-Pro86.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—
LMArena Expert1482—

Multimodal Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 34.8 (#89), Molmo 2 8b: 30.2 (#112)

Multimodal benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Vision—1081
VPCT39.8%—
LMArena Document1450—

Multilingual Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 53.4 (#69), Molmo 2 8b: 42.7 (#190)

Multilingual benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Non-English14251276
LMArena Chinese1459—
LMArena French1458—
LMArena German1427—
LMArena Japanese1390—
LMArena Korean1403—
LMArena Russian1437—
LMArena Spanish1457—

Instruction Following Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 75.0 (#78), Molmo 2 8b: 67.0 (#201)

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Instruction Following14591270
IFEval85%—

Long Context Not comparable

Claude Sonnet 4.5: 45.2 (#46), Molmo 2 8b: —

Long Context benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Longer Query1476—

Writing & Preference Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 66.5 (#34), Molmo 2 8b: 49.4 (#191)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.5Molmo 2 8b
LMArena Text14391288
LMArena Creative Writing1442—
EQ-Bench Creative Writing1678—
WildBench85.4%—
LMArena Multi-Turn1465—

Frequently asked questions

Is Claude Sonnet 4.5 better than Molmo 2 8b?

Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 39.1 on the Noometry Index.

How many benchmarks do Claude Sonnet 4.5 and Molmo 2 8b share?

4 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and Molmo 2 8b has 5.

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