Noometry

Model comparison

Claude Opus 5.5 vs Molmo 2 8b

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 39.1 on the Noometry Index.

Last verified . 5 shared benchmarks.

Claude Opus 5.5 Anthropic

68.6

Rank #3 Confirmed

Molmo 2 8b Allen Institute for AI (Ai2)

39.1

Rank #174 Confirmed

Summary

  • They share 5 benchmarks with published results for both. Claude Opus 5.5 scores higher in 5 categories and Molmo 2 8b in 0 categories; 5 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5.5 leads 80.2 to 25.6.
  • Molmo 2 8b has downloadable open weights; the other is API-only.

Side by side

Claude Opus 5.5Molmo 2 8b
ProviderAnthropicAllen Institute for AI (Ai2)
Noometry Index68.639.1
Released2026-09-22—
WeightsProprietaryOpen
Context window1M—
Max output128K—
Input $ / M tokens$4—
Output $ / M tokens$20—
Results tracked445

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Category by category

Coding Not comparable

Claude Opus 5.5: 71.9 (#3), Molmo 2 8b: —

BenchmarkClaude Opus 5.5Molmo 2 8b
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), Molmo 2 8b: —

BenchmarkClaude Opus 5.5Molmo 2 8b
APEX-Agents73.5%—
GDP.pdf30.6%—
Vending-Bench 29,235—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 80.2 (#3), Molmo 2 8b: 25.6 (#146)

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Hard Prompts15351287
ARC-AGI-293.3%—
NYT Connections (extended)88.5%—
ARC-AGI-198.5%—
CritPt31.7%—
EBR-Bench71.4%—
Mystery Game Puzzles71%—
DTBench98.9%—
LMCA68.2%—
Epoch Capabilities Index167.33—

Math Not comparable

Claude Opus 5.5: 91.8 (#3), Molmo 2 8b: —

BenchmarkClaude Opus 5.5Molmo 2 8b
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), Molmo 2 8b: —

BenchmarkClaude Opus 5.5Molmo 2 8b
GPQA Diamond90.6%—
SimpleQA Verified72.2%—
LMArena Expert1547—

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 57.8 (#1), Molmo 2 8b: 30.2 (#112)

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Vision13211081
Blueprint-Bench 251.2%—
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.1 (#2), Molmo 2 8b: 42.7 (#190)

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Non-English15071276
LMArena Chinese1588—
LMArena French1514—
LMArena Russian1520—
LMArena Spanish1507—

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.0 (#3), Molmo 2 8b: 67.0 (#201)

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Instruction Following15371270

Long Context Not comparable

Claude Opus 5.5: 47.1 (#19), Molmo 2 8b: —

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Longer Query1532—

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.2 (#3), Molmo 2 8b: 49.4 (#191)

BenchmarkClaude Opus 5.5Molmo 2 8b
LMArena Text15151288
LMArena Creative Writing1533—
EQ-Bench Creative Writing2050—
LMArena Multi-Turn1499—

Frequently asked questions

Is Claude Opus 5.5 better than Molmo 2 8b?

Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 39.1 on the Noometry Index.

How many benchmarks do Claude Opus 5.5 and Molmo 2 8b share?

5 benchmarks have published results for both models. Claude Opus 5.5 has 44 scored results on Noometry and Molmo 2 8b has 5.

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