# Claude Sonnet 5.5 vs Gemini 3.1 Pro Preview

> Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 56.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-sonnet-5-5-vs-gemini-3-1-pro-preview
- Last updated: 2026-10-12
- Shared benchmarks: 28

## Summary

- They share 28 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 5 categories and Gemini 3.1 Pro Preview in 5 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 87.9 to 62.1.
- The biggest single-benchmark swing is ProofBench: 100% for Claude Sonnet 5.5 and 26% for Gemini 3.1 Pro Preview.
- Claude Sonnet 5.5 is cheaper at $2 / $10 per million input/output tokens, against $2 / $12 for Gemini 3.1 Pro Preview.
- Gemini 3.1 Pro Preview accepts more context: 1.05M tokens versus 1M.

## Snapshot

| | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| Provider | Anthropic | Google |
| Noometry Index | 61.9 | 56.7 |
| Rank | 10 | 23 |
| Context | 1M | 1.05M |
| Input $/M | $2 | $2 |
| Output $/M | $10 | $12 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Sonnet 5.5: 67.3 (#6)
- Gemini 3.1 Pro Preview: 42.5 (#99)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena WebDev | 1774 | 1447 |
| SciCode | 61% | 58.9% |
| LMArena Coding | 1513 | 1484 |
| ALE-Bench | 1,819 | 1,161 |
| SWE-bench Verified | — | 75.6% |
| DeepSWE | — | 11.7% |
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| FrontierSWE | 61.9% | — |
| GSO | — | 22.6% |
| WeirdML | — | 72.1% |
| MirrorCode | — | 8.9% |
| AlgoTune | — | 2.02 |

## Agentic & Tool Use

- Claude Sonnet 5.5: 45.0 (#16)
- Gemini 3.1 Pro Preview: 37.7 (#34)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| APEX-Agents | 75.5% | 35.3% |
| Terminal-Bench | — | 80.2% |
| τ²-bench Banking | — | 26% |
| DeepResearch Bench | — | 47.8% |
| PostTrainBench | — | 22% |
| BALROG | — | 57% |
| ExploitBench | — | 26.1% |
| GBAEval | — | 0.8% |
| GDP.pdf | — | 17% |
| LMArena Search | — | 1211 |
| METR Time Horizons | — | 77% |
| Vending-Bench 2 | — | 3,774 |

## Reasoning

- Claude Sonnet 5.5: 54.0 (#28)
- Gemini 3.1 Pro Preview: 71.7 (#12)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| NYT Connections (extended) | 80.5% | 97.4% |
| CritPt | 31.4% | 17.7% |
| LMArena Hard Prompts | 1495 | 1485 |
| Mystery Game Puzzles | 65% | 34% |
| Epoch Capabilities Index | 165.03 | 154.77 |
| ARC-AGI-2 | — | 77.1% |
| SimpleBench | — | 79.6% |
| ARC-AGI-1 | — | 98% |
| Chess Puzzles | — | 55% |
| EnigmaEval | — | 36.8% |
| Thematic Generalization | — | 79.4% |
| EBR-Bench | — | 14.3% |
| DTBench | — | 97.1% |
| LMCA | — | 53.8% |
| ForecastBench | — | 59 |

## Math

- Claude Sonnet 5.5: 87.9 (#6)
- Gemini 3.1 Pro Preview: 62.1 (#34)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | 59.6% |
| FrontierMath Tier 4 | 80.5% | 26.8% |
| OTIS Mock AIME 2024-2025 | 100% | 95.6% |
| ProofBench | 100% | 26% |
| LMArena Math | 1510 | 1485 |
| MathArena Final-Answer Competitions | — | 86.5% |
| FrontierMath (Feb 2025 set) | — | 36.9% |
| FrontierMath Erdős | 2.9% | — |
| FrontierMath Tier 4 (v1) | — | 16.7% |

## Knowledge

- Claude Sonnet 5.5: 66.0 (#12)
- Gemini 3.1 Pro Preview: 71.8 (#3)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| GPQA Diamond | 95.6% | 94.4% |
| SimpleQA Verified | 46.5% | 73.5% |
| LMArena Expert | 1540 | 1485 |
| Humanity's Last Exam | — | 46.4% |
| Vectara Hallucination Rate | — | 10.4% |

## Multimodal

- Claude Sonnet 5.5: 51.5 (#6)
- Gemini 3.1 Pro Preview: 37.9 (#69)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena Vision | 1289 | 1296 |
| Furniture Assembly | 75% | 26.7% |
| Blueprint-Bench 2 | — | 26.5% |
| LMArena Document | — | 1444 |

## Multilingual

- Claude Sonnet 5.5: 55.3 (#30)
- Gemini 3.1 Pro Preview: 57.0 (#12)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena Non-English | 1452 | 1477 |
| LMArena Chinese | 1522 | 1529 |
| LMArena Russian | 1451 | 1498 |
| LMArena French | — | 1487 |
| LMArena German | — | 1491 |
| LMArena Japanese | — | 1493 |
| LMArena Korean | — | 1455 |
| LMArena Spanish | — | 1479 |

## Instruction Following

- Claude Sonnet 5.5: 78.3 (#11)
- Gemini 3.1 Pro Preview: 77.0 (#32)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena Instruction Following | 1495 | 1466 |

## Long Context

- Claude Sonnet 5.5: 45.9 (#28)
- Gemini 3.1 Pro Preview: 47.4 (#18)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena Longer Query | 1498 | 1483 |
| CL-bench | — | 20.8% |
| CL-bench Life | — | 16.9% |

## Writing & Preference

- Claude Sonnet 5.5: 66.0 (#40)
- Gemini 3.1 Pro Preview: 66.1 (#37)

| Benchmark | Claude Sonnet 5.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| LMArena Text | 1471 | 1481 |
| LMArena Creative Writing | 1465 | 1482 |
| LMArena Multi-Turn | 1474 | 1488 |
| EQ-Bench Creative Writing | — | 1491 |
| EQ-Bench 4 | — | 1142 |

## FAQ

### Is Claude Sonnet 5.5 better than Gemini 3.1 Pro Preview?

Claude Sonnet 5.5 is the stronger model overall, scoring 61.9 to 56.7 on the Noometry Index.

### Which is cheaper, Claude Sonnet 5.5 or Gemini 3.1 Pro Preview?

Claude Sonnet 5.5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; Gemini 3.1 Pro Preview lists at $2 and $12.

### Is Claude Sonnet 5.5 or Gemini 3.1 Pro Preview better for coding?

Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 42.5 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.1 Pro Preview does, with 1.05M tokens against 1M.

### How many benchmarks do Claude Sonnet 5.5 and Gemini 3.1 Pro Preview share?

28 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and Gemini 3.1 Pro Preview has 71.