# Claude Opus 4.1 vs Mercury 2

> Claude Opus 4.1 is the stronger model overall, scoring 40.8 to 38.8 on the Noometry Index. Mercury 2 costs 80× less per token, which makes it the better buy when Claude Opus 4.1's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-opus-4-1-vs-mercury-2
- Last updated: 2026-10-10
- Shared benchmarks: 15

## Summary

- They share 15 benchmarks with published results for both. Claude Opus 4.1 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 Claude Opus 4.1 leads 44.3 to 33.2.
- Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $15 / $75 for Claude Opus 4.1.
- Claude Opus 4.1 accepts more context: 200K tokens versus 128K.

## Snapshot

| | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| Provider | Anthropic | Inception |
| Noometry Index | 40.8 | 38.8 |
| Rank | 136 | 167 |
| Context | 200K | 128K |
| Input $/M | $15 | $0.25 |
| Output $/M | $75 | $0.75 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 4.1: 44.3 (#69)
- Mercury 2: 33.2 (#250)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena WebDev | 1390 | 1170 |
| WeirdML | 45.9% | 43.2% |
| LMArena Coding | 1479 | 1391 |
| ALE-Bench | 674.77 | 785.58 |
| SWE-bench Verified | 73.3% | — |
| SciCode | — | 38.7% |
| AlgoTune | 1.34 | — |

## Agentic & Tool Use

- Claude Opus 4.1: 34.8 (#38)
- Mercury 2: —

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| Terminal-Bench | 38% | — |
| GDPval | 43.6% | — |
| Cybench | 42% | — |
| DeepResearch Bench | 48.3% | — |
| LMArena Search | 1148 | — |
| METR Time Horizons | 66.8% | — |

## Reasoning

- Claude Opus 4.1: 31.6 (#70)
- Mercury 2: 23.0 (#170)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena Hard Prompts | 1443 | 1362 |
| SimpleBench | 60% | — |
| CritPt | — | 0.8% |
| Chess Puzzles | 7% | — |
| EnigmaEval | 7.2% | — |
| EBR-Bench | 7.9% | — |
| Mystery Game Puzzles | 21% | — |
| DTBench | 80% | — |
| LMCA | 37.1% | — |
| Epoch Capabilities Index | 144.11 | — |
| ForecastBench | 62 | — |

## Math

- Claude Opus 4.1: 22.0 (#267)
- Mercury 2: —

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 12.6% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 68.9% | — |
| LMArena Math | 1430 | — |
| FrontierMath (Feb 2025 set) | 7.2% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Claude Opus 4.1: 41.9 (#93)
- Mercury 2: 35.6 (#170)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| Vectara Hallucination Rate | 11.8% | 12.3% |
| LMArena Expert | 1439 | 1358 |
| GPQA Diamond | 77.3% | — |
| Humanity's Last Exam | 11.5% | — |
| Confabulations | 17.1% | — |

## Multimodal

- Claude Opus 4.1: 26.2 (#114)
- Mercury 2: —

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| VPCT | 35% | — |

## Multilingual

- Claude Opus 4.1: 52.1 (#90)
- Mercury 2: 46.8 (#153)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1405 | 1331 |
| LMArena Chinese | 1427 | 1416 |
| LMArena Russian | 1421 | 1303 |
| LMArena French | 1432 | — |
| LMArena German | 1412 | — |
| LMArena Japanese | 1378 | — |
| LMArena Korean | 1381 | — |
| LMArena Spanish | 1448 | — |

## Instruction Following

- Claude Opus 4.1: 75.8 (#53)
- Mercury 2: 70.4 (#161)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1436 | 1328 |

## Long Context

- Claude Opus 4.1: 44.5 (#60)
- Mercury 2: 40.4 (#149)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1455 | 1329 |

## Writing & Preference

- Claude Opus 4.1: 62.6 (#70)
- Mercury 2: 54.0 (#151)

| Benchmark | Claude Opus 4.1 | Mercury 2 |
|---|---|---|
| LMArena Text | 1419 | 1355 |
| LMArena Creative Writing | 1412 | 1289 |
| LMArena Multi-Turn | 1444 | 1358 |
| Short-Story Creative Writing | 84.7% | — |

## FAQ

### Is Claude Opus 4.1 better than Mercury 2?

Claude Opus 4.1 is the stronger model overall, scoring 40.8 to 38.8 on the Noometry Index. Mercury 2 costs 80× less per token, which makes it the better buy when Claude Opus 4.1's lead doesn't matter for your workload.

### Which is cheaper, Claude Opus 4.1 or Mercury 2?

Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; Claude Opus 4.1 lists at $15 and $75.

### Is Claude Opus 4.1 or Mercury 2 better for coding?

Claude Opus 4.1 scores higher on coding benchmarks: 44.3 versus 33.2 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 4.1 does, with 200K tokens against 128K.

### How many benchmarks do Claude Opus 4.1 and Mercury 2 share?

15 benchmarks have published results for both models. Claude Opus 4.1 has 48 scored results on Noometry and Mercury 2 has 17.