Model comparison
Claude Sonnet 5.5 vs Molmo 2 8b
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 39.1 on the Noometry Index.
Last verified . 5 shared benchmarks.
Allen Institute for AI (Ai2)Summary
- They share 5 benchmarks with published results for both. Claude Sonnet 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 Sonnet 5.5 leads 54.0 to 25.6.
- Molmo 2 8b has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5.5 | Molmo 2 8b | |
|---|---|---|
| Provider | Anthropic | Allen Institute for AI (Ai2) |
| Noometry Index | 61.9 | 39.1 |
| Released | 2026-09-28 | — |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $2 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 32 | 5 |
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Category by category
Coding Not comparable
Claude Sonnet 5.5: 67.3 (#6), Molmo 2 8b: —
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1774 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| LMArena Coding | 1513 | — |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 45.0 (#16), Molmo 2 8b: —
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| APEX-Agents | 75.5% | — |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 54.0 (#28), Molmo 2 8b: 25.6 (#146)
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Hard Prompts | 1495 | 1287 |
| NYT Connections (extended) | 80.5% | — |
| CritPt | 31.4% | — |
| Mystery Game Puzzles | 65% | — |
| Epoch Capabilities Index | 165.03 | — |
Math Not comparable
Claude Sonnet 5.5: 87.9 (#6), Molmo 2 8b: —
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| LMArena Math | 1510 | — |
| FrontierMath Erdős | 2.9% | — |
Knowledge Not comparable
Claude Sonnet 5.5: 66.0 (#12), Molmo 2 8b: —
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| GPQA Diamond | 95.6% | — |
| SimpleQA Verified | 46.5% | — |
| LMArena Expert | 1540 | — |
Multimodal Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 51.5 (#6), Molmo 2 8b: 30.2 (#112)
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Vision | 1289 | 1081 |
| Furniture Assembly | 75% | — |
Multilingual Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 55.3 (#30), Molmo 2 8b: 42.7 (#190)
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Non-English | 1452 | 1276 |
| LMArena Chinese | 1522 | — |
| LMArena Russian | 1451 | — |
Instruction Following Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 78.3 (#11), Molmo 2 8b: 67.0 (#201)
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Instruction Following | 1495 | 1270 |
Long Context Not comparable
Claude Sonnet 5.5: 45.9 (#28), Molmo 2 8b: —
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Longer Query | 1498 | — |
Writing & Preference Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#40), Molmo 2 8b: 49.4 (#191)
| Benchmark | Claude Sonnet 5.5 | Molmo 2 8b |
|---|---|---|
| LMArena Text | 1471 | 1288 |
| LMArena Creative Writing | 1465 | — |
| LMArena Multi-Turn | 1474 | — |
Frequently asked questions
Is Claude Sonnet 5.5 better than Molmo 2 8b?
Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 39.1 on the Noometry Index.
How many benchmarks do Claude Sonnet 5.5 and Molmo 2 8b share?
5 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Molmo 2 8b has 5.