# Grok 4.3 vs Mercury 2

> Grok 4.3 is the stronger model overall, scoring 43.8 to 39.1 on the Noometry Index. Mercury 2 costs 4.2× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/grok-4-3-vs-mercury-2
- Last updated: 2026-10-10
- Shared benchmarks: 16

## Summary

- They share 16 benchmarks with published results for both. Grok 4.3 scores higher in 7 categories and Mercury 2 in 0 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where Grok 4.3 leads 52.5 to 36.2.
- The biggest single-benchmark swing is SciCode: 47.3% for Grok 4.3 and 38.7% for Mercury 2.
- Mercury 2 is cheaper at $0.25 / $0.75 per million input/output tokens, against $1.25 / $2.50 for Grok 4.3.
- Grok 4.3 accepts more context: 1M tokens versus 128K.

## Snapshot

| | Grok 4.3 | Mercury 2 |
|---|---|---|
| Provider | xAI | Inception |
| Noometry Index | 43.8 | 39.1 |
| Rank | 86 | 175 |
| Context | 1M | 128K |
| Input $/M | $1.25 | $0.25 |
| Output $/M | $2.50 | $0.75 |
| Weights | Proprietary | Proprietary |

## Coding

- Grok 4.3: 41.6 (#121)
- Mercury 2: 33.5 (#255)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena WebDev | 1357 | 1171 |
| SciCode | 47.3% | 38.7% |
| WeirdML | 49.9% | 43.2% |
| LMArena Coding | 1415 | 1391 |
| ALE-Bench | 944.17 | 785.58 |

## Agentic & Tool Use

- Grok 4.3: 27.7 (#99)
- Mercury 2: —

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| GDP.pdf | 8% | — |
| LMArena Search | 1165 | — |
| Vending-Bench 2 | 35.26 | — |

## Reasoning

- Grok 4.3: 35.9 (#68)
- Mercury 2: 23.8 (#170)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| CritPt | 8% | 0.8% |
| LMArena Hard Prompts | 1396 | 1362 |
| NYT Connections (extended) | 55.2% | — |
| Chess Puzzles | 25% | — |
| DTBench | 90.7% | — |
| LMCA | 38.3% | — |
| Epoch Capabilities Index | 149.16 | — |
| ForecastBench | 60.3 | — |

## Math

- Grok 4.3: 46.0 (#74)
- Mercury 2: —

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 42.8% | — |
| FrontierMath Tier 4 | 14.6% | — |
| OTIS Mock AIME 2024-2025 | 93.3% | — |
| ProofBench | 11% | — |
| LMArena Math | 1388 | — |

## Knowledge

- Grok 4.3: 52.5 (#62)
- Mercury 2: 36.2 (#172)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Expert | 1385 | 1358 |
| GPQA Diamond | 88.8% | — |
| SimpleQA Verified | 33.2% | — |
| Vectara Hallucination Rate | — | 12.3% |

## Multimodal

- Grok 4.3: 31.6 (#104)
- Mercury 2: —

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Vision | 1229 | — |
| Blueprint-Bench 2 | 0% | — |

## Multilingual

- Grok 4.3: 50.5 (#120)
- Mercury 2: 46.6 (#157)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Non-English | 1385 | 1331 |
| LMArena Chinese | 1422 | 1417 |
| LMArena Russian | 1399 | 1304 |
| LMArena French | 1412 | — |
| LMArena German | 1395 | — |
| LMArena Japanese | 1379 | — |
| LMArena Korean | 1356 | — |
| LMArena Spanish | 1398 | — |

## Instruction Following

- Grok 4.3: 72.1 (#140)
- Mercury 2: 70.2 (#165)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Instruction Following | 1366 | 1329 |

## Long Context

- Grok 4.3: 42.5 (#123)
- Mercury 2: 40.5 (#154)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Longer Query | 1393 | 1330 |

## Writing & Preference

- Grok 4.3: 58.5 (#118)
- Mercury 2: 53.8 (#155)

| Benchmark | Grok 4.3 | Mercury 2 |
|---|---|---|
| LMArena Text | 1397 | 1355 |
| LMArena Creative Writing | 1380 | 1289 |
| LMArena Multi-Turn | 1406 | 1358 |
| EQ-Bench 4 | 1075 | — |

## FAQ

### Is Grok 4.3 better than Mercury 2?

Grok 4.3 is the stronger model overall, scoring 43.8 to 39.1 on the Noometry Index. Mercury 2 costs 4.2× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

### Which is cheaper, Grok 4.3 or Mercury 2?

Mercury 2 is cheaper. It lists at $0.25 per million input tokens and $0.75 per million output tokens; Grok 4.3 lists at $1.25 and $2.50.

### Is Grok 4.3 or Mercury 2 better for coding?

Grok 4.3 scores higher on coding benchmarks: 41.6 versus 33.5 in the Noometry coding category.

### Which has the bigger context window?

Grok 4.3 does, with 1M tokens against 128K.

### How many benchmarks do Grok 4.3 and Mercury 2 share?

16 benchmarks have published results for both models. Grok 4.3 has 40 scored results on Noometry and Mercury 2 has 17.