# Gemini 3.1 Pro Preview vs Mercury 2

> Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 38.8 on the Noometry Index. Mercury 2 costs 12× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-3-1-pro-preview-vs-mercury-2
- Last updated: 2026-10-10
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. Gemini 3.1 Pro Preview scores higher in 7 categories and Mercury 2 in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.1 Pro Preview leads 71.7 to 23.0.
- The biggest single-benchmark swing is WeirdML: 72.1% for Gemini 3.1 Pro Preview and 43.2% for Mercury 2.
- Mercury 2 is cheaper at $0.25 / $0.75 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 128K.

## Snapshot

| | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| Provider | Google | Inception |
| Noometry Index | 56.7 | 38.8 |
| Rank | 20 | 167 |
| Context | 1.05M | 128K |
| Input $/M | $2 | $0.25 |
| Output $/M | $12 | $0.75 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.1 Pro Preview: 42.7 (#88)
- Mercury 2: 33.2 (#250)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena WebDev | 1446 | 1170 |
| SciCode | 58.9% | 38.7% |
| WeirdML | 72.1% | 43.2% |
| LMArena Coding | 1483 | 1391 |
| ALE-Bench | 1,161 | 785.58 |
| SWE-bench Verified | 75.6% | — |
| DeepSWE | 11.7% | — |
| GSO | 22.6% | — |
| MirrorCode | 8.9% | — |
| AlgoTune | 2.02 | — |

## Agentic & Tool Use

- Gemini 3.1 Pro Preview: 37.7 (#33)
- Mercury 2: —

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| Terminal-Bench | 80.2% | — |
| APEX-Agents | 35.3% | — |
| 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

- Gemini 3.1 Pro Preview: 71.7 (#9)
- Mercury 2: 23.0 (#170)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| CritPt | 17.7% | 0.8% |
| LMArena Hard Prompts | 1484 | 1362 |
| ARC-AGI-2 | 77.1% | — |
| SimpleBench | 79.6% | — |
| NYT Connections (extended) | 97.4% | — |
| ARC-AGI-1 | 98% | — |
| Chess Puzzles | 55% | — |
| EnigmaEval | 36.8% | — |
| Thematic Generalization | 79.4% | — |
| EBR-Bench | 14.3% | — |
| Mystery Game Puzzles | 34% | — |
| DTBench | 97.1% | — |
| LMCA | 53.8% | — |
| Epoch Capabilities Index | 154.92 | — |
| ForecastBench | 59 | — |

## Math

- Gemini 3.1 Pro Preview: 61.8 (#28)
- Mercury 2: —

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 59.6% | — |
| FrontierMath Tier 4 | 26.8% | — |
| MathArena Final-Answer Competitions | 86.5% | — |
| OTIS Mock AIME 2024-2025 | 95.6% | — |
| ProofBench | 26% | — |
| LMArena Math | 1485 | — |
| FrontierMath (Feb 2025 set) | 36.9% | — |
| FrontierMath Tier 4 (v1) | 16.7% | — |

## Knowledge

- Gemini 3.1 Pro Preview: 71.8 (#3)
- Mercury 2: 35.6 (#170)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| Vectara Hallucination Rate | 10.4% | 12.3% |
| LMArena Expert | 1484 | 1358 |
| GPQA Diamond | 94.4% | — |
| Humanity's Last Exam | 46.4% | — |
| SimpleQA Verified | 73.5% | — |

## Multimodal

- Gemini 3.1 Pro Preview: 38.1 (#60)
- Mercury 2: —

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena Vision | 1296 | — |
| Blueprint-Bench 2 | 26.5% | — |
| Furniture Assembly | 26.7% | — |
| LMArena Document | 1444 | — |

## Multilingual

- Gemini 3.1 Pro Preview: 57.1 (#11)
- Mercury 2: 46.8 (#153)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1475 | 1331 |
| LMArena Chinese | 1528 | 1416 |
| LMArena Russian | 1496 | 1303 |
| LMArena French | 1488 | — |
| LMArena German | 1491 | — |
| LMArena Japanese | 1494 | — |
| LMArena Korean | 1458 | — |
| LMArena Spanish | 1480 | — |

## Instruction Following

- Gemini 3.1 Pro Preview: 77.1 (#31)
- Mercury 2: 70.4 (#161)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1465 | 1328 |

## Long Context

- Gemini 3.1 Pro Preview: 47.3 (#17)
- Mercury 2: 40.4 (#149)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1482 | 1329 |
| CL-bench | 20.8% | — |
| CL-bench Life | 16.9% | — |

## Writing & Preference

- Gemini 3.1 Pro Preview: 66.3 (#36)
- Mercury 2: 54.0 (#151)

| Benchmark | Gemini 3.1 Pro Preview | Mercury 2 |
|---|---|---|
| LMArena Text | 1480 | 1355 |
| LMArena Creative Writing | 1482 | 1289 |
| LMArena Multi-Turn | 1486 | 1358 |
| EQ-Bench Creative Writing | 1491 | — |
| EQ-Bench 4 | 1142 | — |

## FAQ

### Is Gemini 3.1 Pro Preview better than Mercury 2?

Gemini 3.1 Pro Preview is the stronger model overall, scoring 56.7 to 38.8 on the Noometry Index. Mercury 2 costs 12× less per token, which makes it the better buy when Gemini 3.1 Pro Preview's lead doesn't matter for your workload.

### Which is cheaper, Gemini 3.1 Pro Preview or Mercury 2?

Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; Gemini 3.1 Pro Preview lists at $2 and $12.

### Is Gemini 3.1 Pro Preview or Mercury 2 better for coding?

Gemini 3.1 Pro Preview scores higher on coding benchmarks: 42.7 versus 33.2 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.1 Pro Preview does, with 1.05M tokens against 128K.

### How many benchmarks do Gemini 3.1 Pro Preview and Mercury 2 share?

17 benchmarks have published results for both models. Gemini 3.1 Pro Preview has 71 scored results on Noometry and Mercury 2 has 17.