# Mercury vs o3-pro

> o3-pro is the stronger model overall, scoring 42.7 to 37.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/mercury-vs-o3-pro
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. Mercury scores higher in 0 categories and o3-pro in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where o3-pro leads 72.1 to 38.3.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 21.6% for Mercury and 72.1% for o3-pro.

## Snapshot

| | Mercury | o3-pro |
|---|---|---|
| Provider | Inception | OpenAI |
| Noometry Index | 37.3 | 42.7 |
| Rank | 192 | 94 |
| Context | — | 200K |
| Input $/M | — | $20 |
| Output $/M | — | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- Mercury: 38.1 (#164)
- o3-pro: 55.1 (#22)

| Benchmark | Mercury | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| WeirdML | — | 58.2% |
| LMArena Coding | 1323 | — |

## Reasoning

- Mercury: 16.8 (#288)
- o3-pro: 24.1 (#152)

| Benchmark | Mercury | o3-pro |
|---|---|---|
| Kagi LLM Benchmark | 21.6% | 72.1% |
| ARC-AGI-2 | — | 4.9% |
| ARC-AGI-1 | — | 59.3% |
| LMArena Hard Prompts | 1284 | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
| Epoch Capabilities Index | — | 147.43 |

## Knowledge

- Mercury: —
- o3-pro: 29.0 (#234)

| Benchmark | Mercury | o3-pro |
|---|---|---|
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |

## Multilingual

- Mercury: 41.7 (#201)
- o3-pro: —

| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Non-English | 1259 | — |

## Instruction Following

- Mercury: 65.3 (#220)
- o3-pro: —

| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1238 | — |

## Long Context

- Mercury: 38.3 (#193)
- o3-pro: 72.1 (#1)

| Benchmark | Mercury | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1264 | — |

## Writing & Preference

- Mercury: 46.2 (#216)
- o3-pro: 57.1 (#128)

| Benchmark | Mercury | o3-pro |
|---|---|---|
| LMArena Text | 1282 | — |
| LMArena Creative Writing | 1186 | — |
| Short-Story Creative Writing | — | 84.4% |
| LMArena Multi-Turn | 1283 | — |

## FAQ

### Is Mercury better than o3-pro?

o3-pro is the stronger model overall, scoring 42.7 to 37.3 on the Noometry Index.

### Is Mercury or o3-pro better for coding?

o3-pro scores higher on coding benchmarks: 55.1 versus 38.1 in the Noometry coding category.

### How many benchmarks do Mercury and o3-pro share?

1 benchmark has published results for both models. Mercury has 9 scored results on Noometry and o3-pro has 12.