# GPT-4.5 vs Mercury 2

> Mercury 2 is the stronger model overall, scoring 39.1 to 37.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-4-5-vs-mercury-2
- Last updated: 2026-10-10
- Shared benchmarks: 12

## Summary

- They share 12 benchmarks with published results for both. GPT-4.5 scores higher in 4 categories and Mercury 2 in 3 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Mercury 2 leads 23.8 to 13.9.

## Snapshot

| | GPT-4.5 | Mercury 2 |
|---|---|---|
| Provider | OpenAI | Inception |
| Noometry Index | 37.2 | 39.1 |
| Rank | 208 | 175 |
| Context | — | 128K |
| Input $/M | — | $0.25 |
| Output $/M | — | $0.75 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-4.5: 42.2 (#109)
- Mercury 2: 33.5 (#255)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| WeirdML | 39.4% | 43.2% |
| LMArena Coding | 1396 | 1391 |
| Aider Polyglot | 44.9% | — |
| LMArena WebDev | — | 1171 |
| SciCode | — | 38.7% |
| LiveBench Coding | 75.2% | — |
| ALE-Bench | — | 785.58 |

## Agentic & Tool Use

- GPT-4.5: 27.9 (#97)
- Mercury 2: —

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| Cybench | 17.5% | — |

## Reasoning

- GPT-4.5: 13.9 (#330)
- Mercury 2: 23.8 (#170)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Hard Prompts | 1403 | 1362 |
| ARC-AGI-2 | 0.8% | — |
| SimpleBench | 34.5% | — |
| ARC-AGI-1 | 10.3% | — |
| CritPt | — | 0.8% |
| EnigmaEval | 3.2% | — |
| LiveBench Reasoning | 71.1% | — |
| LiveBench Data Analysis | 64.3% | — |
| Epoch Capabilities Index | 136.74 | — |
| ForecastBench | 61.7 | — |
| LiveBench | 69% | — |

## Math

- GPT-4.5: 32.6 (#211)
- Mercury 2: —

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 37.8% | — |
| LiveBench Math | 69.3% | — |
| LMArena Math | 1412 | — |
| MATH Level 5 | 78.6% | — |

## Knowledge

- GPT-4.5: 32.5 (#211)
- Mercury 2: 36.2 (#172)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Expert | 1394 | 1358 |
| GPQA Diamond | 68.7% | — |
| Humanity's Last Exam | 5.4% | — |
| Confabulations | 13.6% | — |
| Vectara Hallucination Rate | — | 12.3% |

## Multimodal

- GPT-4.5: 37.6 (#71)
- Mercury 2: —

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Vision | 1195 | — |
| VPCT | 45% | — |

## Multilingual

- GPT-4.5: 52.5 (#83)
- Mercury 2: 46.6 (#157)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1413 | 1331 |
| LMArena Chinese | 1421 | 1417 |
| LMArena Russian | 1419 | 1304 |
| LMArena French | 1418 | — |
| LMArena German | 1457 | — |
| LMArena Japanese | 1416 | — |
| LMArena Korean | 1392 | — |

## Instruction Following

- GPT-4.5: 72.6 (#134)
- Mercury 2: 70.2 (#165)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1404 | 1329 |
| LiveBench Instruction Following | 72.3% | — |

## Long Context

- GPT-4.5: 40.4 (#155)
- Mercury 2: 40.5 (#154)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1406 | 1330 |
| Fiction.LiveBench | 63.9% | — |

## Writing & Preference

- GPT-4.5: 56.9 (#134)
- Mercury 2: 53.8 (#155)

| Benchmark | GPT-4.5 | Mercury 2 |
|---|---|---|
| LMArena Text | 1417 | 1355 |
| LMArena Creative Writing | 1394 | 1289 |
| LMArena Multi-Turn | 1444 | 1358 |
| Short-Story Creative Writing | 75.6% | — |
| EQ-Bench Creative Writing | 1258 | — |
| LiveBench Language | 61.5% | — |

## FAQ

### Is GPT-4.5 better than Mercury 2?

Mercury 2 is the stronger model overall, scoring 39.1 to 37.2 on the Noometry Index.

### Is GPT-4.5 or Mercury 2 better for coding?

GPT-4.5 scores higher on coding benchmarks: 42.2 versus 33.5 in the Noometry coding category.

### How many benchmarks do GPT-4.5 and Mercury 2 share?

12 benchmarks have published results for both models. GPT-4.5 has 42 scored results on Noometry and Mercury 2 has 17.