# GPT-6 Luna vs Mercury 2

> GPT-6 Luna is the stronger model overall, scoring 45.1 to 38.8 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-6-luna-vs-mercury-2
- Last updated: 2026-10-10
- Shared benchmarks: 12

## Summary

- They share 12 benchmarks with published results for both. GPT-6 Luna scores higher in 7 categories and Mercury 2 in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in coding, where GPT-6 Luna leads 54.7 to 33.2.
- GPT-6 Luna is cheaper at $0.10 / $0.50 per million input/output tokens, against $0.25 / $0.75 for Mercury 2.
- GPT-6 Luna accepts more context: 1.05M tokens versus 128K.

## Snapshot

| | GPT-6 Luna | Mercury 2 |
|---|---|---|
| Provider | OpenAI | Inception |
| Noometry Index | 45.1 | 38.8 |
| Rank | 65 | 167 |
| Context | 1.05M | 128K |
| Input $/M | $0.10 | $0.25 |
| Output $/M | $0.50 | $0.75 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-6 Luna: 54.7 (#24)
- Mercury 2: 33.2 (#250)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena WebDev | 1583 | 1170 |
| LMArena Coding | 1448 | 1391 |
| DeepSWE | 66.6% | — |
| FrontierCode | 42.4% | — |
| SciCode | — | 38.7% |
| WeirdML | — | 43.2% |
| ALE-Bench | — | 785.58 |

## Reasoning

- GPT-6 Luna: 31.7 (#68)
- Mercury 2: 23.0 (#170)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Hard Prompts | 1415 | 1362 |
| NYT Connections (extended) | 68.7% | — |
| CritPt | — | 0.8% |

## Math

- GPT-6 Luna: 35.6 (#140)
- Mercury 2: —

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Math | 1396 | — |

## Knowledge

- GPT-6 Luna: 40.1 (#110)
- Mercury 2: 35.6 (#170)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Expert | 1458 | 1358 |
| Vectara Hallucination Rate | — | 12.3% |

## Multimodal

- GPT-6 Luna: 42.0 (#27)
- Mercury 2: —

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| Furniture Assembly | 44.2% | — |

## Multilingual

- GPT-6 Luna: 51.0 (#111)
- Mercury 2: 46.8 (#153)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1390 | 1331 |
| LMArena Chinese | 1425 | 1416 |
| LMArena Russian | 1392 | 1303 |
| LMArena Spanish | 1416 | — |

## Instruction Following

- GPT-6 Luna: 74.7 (#85)
- Mercury 2: 70.4 (#161)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1414 | 1328 |

## Long Context

- GPT-6 Luna: 43.3 (#95)
- Mercury 2: 40.4 (#149)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1417 | 1329 |

## Writing & Preference

- GPT-6 Luna: 58.4 (#115)
- Mercury 2: 54.0 (#151)

| Benchmark | GPT-6 Luna | Mercury 2 |
|---|---|---|
| LMArena Text | 1392 | 1355 |
| LMArena Creative Writing | 1357 | 1289 |
| LMArena Multi-Turn | 1400 | 1358 |

## FAQ

### Is GPT-6 Luna better than Mercury 2?

GPT-6 Luna is the stronger model overall, scoring 45.1 to 38.8 on the Noometry Index.

### Which is cheaper, GPT-6 Luna or Mercury 2?

GPT-6 Luna is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; Mercury 2 lists at $0.25 and $0.75.

### Is GPT-6 Luna or Mercury 2 better for coding?

GPT-6 Luna scores higher on coding benchmarks: 54.7 versus 33.2 in the Noometry coding category.

### Which has the bigger context window?

GPT-6 Luna does, with 1.05M tokens against 128K.

### How many benchmarks do GPT-6 Luna and Mercury 2 share?

12 benchmarks have published results for both models. GPT-6 Luna has 18 scored results on Noometry and Mercury 2 has 17.