Model comparison
Claude Opus 5.5 vs Molmo 2 8b
Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 38.7 on the Noometry Index.
Last verified . 4 shared benchmarks.
Allen Institute for AI (Ai2)Summary
- They share 4 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 79.5 to 24.5.
- Molmo 2 8b has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 5.5 | Molmo 2 8b | |
|---|---|---|
| Provider | Anthropic | Allen Institute for AI (Ai2) |
| Noometry Index | 68.5 | 38.7 |
| Released | 2026-09-22 | — |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $4 | — |
| Output $ / M tokens | $20 | — |
| Results tracked | 35 | 5 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding Not comparable
Claude Opus 5.5: 71.4 (#1), Molmo 2 8b: —
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| FrontierCode | 54.4% | — |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1820 | — |
| FrontierSWE | 62.3% | — |
| SciCode | 66.9% | — |
| LMArena Coding | 1545 | — |
| MirrorCode | 77.4% | — |
Agentic & Tool Use Not comparable
Claude Opus 5.5: 45.3 (#13), Molmo 2 8b: —
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| APEX-Agents | 73.5% | — |
| GDP.pdf | 30.6% | — |
Reasoning Claude Opus 5.5 leads
Claude Opus 5.5: 79.5 (#2), Molmo 2 8b: 24.5 (#146)
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Hard Prompts | 1545 | 1288 |
| ARC-AGI-2 | 92.5% | — |
| NYT Connections (extended) | 88.5% | — |
| ARC-AGI-1 | 97.5% | — |
| CritPt | 31.7% | — |
| EBR-Bench | 71.4% | — |
| Mystery Game Puzzles | 71% | — |
| DTBench | 98.9% | — |
| LMCA | 68.2% | — |
Math Not comparable
Claude Opus 5.5: 92.4 (#2), Molmo 2 8b: —
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
Knowledge Not comparable
Claude Opus 5.5: 66.6 (#9), Molmo 2 8b: —
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| GPQA Diamond | 90.6% | — |
| SimpleQA Verified | 72.2% | — |
| LMArena Expert | 1564 | — |
Multimodal Claude Opus 5.5 leads
Claude Opus 5.5: 56.5 (#2), Molmo 2 8b: 29.5 (#106)
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Vision | — | 1081 |
| Furniture Assembly | 83.3% | — |
Multilingual Claude Opus 5.5 leads
Claude Opus 5.5: 59.8 (#1), Molmo 2 8b: 42.8 (#186)
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Non-English | 1513 | 1275 |
| LMArena Chinese | 1572 | — |
| LMArena Russian | 1532 | — |
Instruction Following Claude Opus 5.5 leads
Claude Opus 5.5: 80.1 (#2), Molmo 2 8b: 67.2 (#196)
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Instruction Following | 1535 | 1270 |
Long Context Not comparable
Claude Opus 5.5: 47.3 (#18), Molmo 2 8b: —
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Longer Query | 1540 | — |
Writing & Preference Claude Opus 5.5 leads
Claude Opus 5.5: 78.7 (#3), Molmo 2 8b: 49.5 (#187)
| Benchmark | Claude Opus 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Text | 1518 | 1288 |
| LMArena Creative Writing | 1538 | — |
| EQ-Bench Creative Writing | 2050 | — |
| LMArena Multi-Turn | 1520 | — |
Frequently asked questions
Is Claude Opus 5.5 better than Molmo 2 8b?
Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 38.7 on the Noometry Index.
How many benchmarks do Claude Opus 5.5 and Molmo 2 8b share?
4 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Molmo 2 8b has 5.