# Mercury 2.5 vs o3-pro

> o3-pro is the stronger model overall, scoring 42.9 to 33.5 on the Noometry Index. Mercury 2.5 costs 519× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/mercury-2-5-vs-o3-pro
- Last updated: 2026-10-12
- Shared benchmarks: 0

## Summary

- The widest gap is in coding, where o3-pro leads 55.5 to 39.5.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $20 / $80 for o3-pro.
- Mercury 2.5 accepts more context: 260K tokens versus 200K.

## Snapshot

| | Mercury 2.5 | o3-pro |
|---|---|---|
| Provider | Inception | OpenAI |
| Noometry Index | 33.5 | 42.9 |
| Rank | 242 | 105 |
| Context | 260K | 200K |
| Input $/M | $0.04 | $20 |
| Output $/M | $0.15 | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- Mercury 2.5: 39.5 (#156)
- o3-pro: 55.5 (#24)

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| SciCode | 38.5% | — |
| WeirdML | — | 58.2% |
| ALE-Bench | 301.65 | — |

## Reasoning

- Mercury 2.5: 22.4 (#193)
- o3-pro: 23.8 (#171)

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| ARC-AGI-2 | — | 4.9% |
| Kagi LLM Benchmark | — | 72.1% |
| ARC-AGI-1 | — | 59.3% |
| CritPt | 0% | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
| Epoch Capabilities Index | — | 147.42 |

## Math

- Mercury 2.5: 23.3 (#272)
- o3-pro: —

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| ProofBench | 3% | — |

## Knowledge

- Mercury 2.5: —
- o3-pro: 29.5 (#238)

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |

## Long Context

- Mercury 2.5: —
- o3-pro: 72.2 (#1)

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |

## Writing & Preference

- Mercury 2.5: —
- o3-pro: 57.1 (#133)

| Benchmark | Mercury 2.5 | o3-pro |
|---|---|---|
| Short-Story Creative Writing | — | 84.4% |

## FAQ

### Is Mercury 2.5 better than o3-pro?

o3-pro is the stronger model overall, scoring 42.9 to 33.5 on the Noometry Index. Mercury 2.5 costs 519× less per token, which makes it the better buy when o3-pro's lead doesn't matter for your workload.

### Which is cheaper, Mercury 2.5 or o3-pro?

Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; o3-pro lists at $20 and $80.

### Is Mercury 2.5 or o3-pro better for coding?

o3-pro scores higher on coding benchmarks: 55.5 versus 39.5 in the Noometry coding category.

### Which has the bigger context window?

Mercury 2.5 does, with 260K tokens against 200K.

### How many benchmarks do Mercury 2.5 and o3-pro share?

0 benchmarks have published results for both models. Mercury 2.5 has 4 scored results on Noometry and o3-pro has 12.