# Grok 4.20 (Non-Reasoning) vs Mercury 2.5

> Grok 4.20 (Non-Reasoning) has enough public results to be ranked (#48); Mercury 2.5 does not yet, so treat this comparison as directional.

- Canonical page: https://noometry.com/compare/grok-4-20-vs-mercury-2-5
- Last updated: 2026-10-10
- Shared benchmarks: 2

## Summary

- They share 2 benchmarks with published results for both. Grok 4.20 (Non-Reasoning) scores higher in 1 category and Mercury 2.5 in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in math, where Grok 4.20 (Non-Reasoning) leads 48.0 to 22.4.
- The biggest single-benchmark swing is ProofBench: 14% for Grok 4.20 (Non-Reasoning) and 3% for Mercury 2.5.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 (Non-Reasoning).
- Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 260K.

## Snapshot

| | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| Provider | xAI | Inception |
| Noometry Index | 48.5 | 30.2 |
| Rank | 48 | — |
| Context | 1M | 260K |
| Input $/M | $1.25 | $0.04 |
| Output $/M | $2.50 | $0.15 |
| Weights | Proprietary | Proprietary |

## Coding

- Grok 4.20 (Non-Reasoning): 41.8 (#104)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| ALE-Bench | 1,150 | 301.65 |
| LMArena WebDev | 1374 | — |
| WeirdML | 52.3% | — |
| LMArena Coding | 1458 | — |

## Agentic & Tool Use

- Grok 4.20 (Non-Reasoning): 34.3 (#43)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| Terminal-Bench | 57.3% | — |
| τ²-bench Banking | 18% | — |
| LMArena Search | 1189 | — |
| Vending-Bench 2 | 4,663 | — |

## Reasoning

- Grok 4.20 (Non-Reasoning): 52.2 (#30)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| ARC-AGI-2 | 65.1% | — |
| Kagi LLM Benchmark | 75% | — |
| NYT Connections (extended) | 85.4% | — |
| ARC-AGI-1 | 89.5% | — |
| Chess Puzzles | 24% | — |
| Thematic Generalization | 63.8% | — |
| LMArena Hard Prompts | 1451 | — |
| DTBench | 90.1% | — |
| LMCA | 38.7% | — |
| Epoch Capabilities Index | 152.01 | — |
| ForecastBench | 61.4 | — |

## Math

- Grok 4.20 (Non-Reasoning): 48.0 (#54)
- Mercury 2.5: 22.4

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| ProofBench | 14% | 3% |
| FrontierMath (Tiers 1-3) | 44.9% | — |
| FrontierMath Tier 4 | 17.1% | — |
| OTIS Mock AIME 2024-2025 | 92.2% | — |
| LMArena Math | 1455 | — |

## Knowledge

- Grok 4.20 (Non-Reasoning): 52.8 (#54)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| GPQA Diamond | 89.3% | — |
| SimpleQA Verified | 30.2% | — |
| LMArena Expert | 1440 | — |

## Multimodal

- Grok 4.20 (Non-Reasoning): 33.2 (#88)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| LMArena Vision | 1263 | — |
| Blueprint-Bench 2 | 0% | — |
| LMArena Document | 1416 | — |

## Multilingual

- Grok 4.20 (Non-Reasoning): 54.7 (#38)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| LMArena Non-English | 1440 | — |
| LMArena Chinese | 1481 | — |
| LMArena French | 1477 | — |
| LMArena German | 1463 | — |
| LMArena Japanese | 1450 | — |
| LMArena Korean | 1417 | — |
| LMArena Russian | 1457 | — |
| LMArena Spanish | 1442 | — |

## Instruction Following

- Grok 4.20 (Non-Reasoning): 75.0 (#79)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| LMArena Instruction Following | 1420 | — |

## Long Context

- Grok 4.20 (Non-Reasoning): 45.4 (#33)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| CL-bench | 22.2% | — |
| CL-bench Life | 11.9% | — |
| LMArena Longer Query | 1436 | — |

## Writing & Preference

- Grok 4.20 (Non-Reasoning): 65.9 (#42)
- Mercury 2.5: —

| Benchmark | Grok 4.20 (Non-Reasoning) | Mercury 2.5 |
|---|---|---|
| LMArena Text | 1451 | — |
| LMArena Creative Writing | 1439 | — |
| EQ-Bench Creative Writing | 1574 | — |
| LMArena Multi-Turn | 1456 | — |

## FAQ

### Is Grok 4.20 (Non-Reasoning) better than Mercury 2.5?

Grok 4.20 (Non-Reasoning) has enough public results to be ranked (#48); Mercury 2.5 does not yet, so treat this comparison as directional.

### Which is cheaper, Grok 4.20 (Non-Reasoning) or Mercury 2.5?

Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; Grok 4.20 (Non-Reasoning) lists at $1.25 and $2.50.

### Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 260K.

### How many benchmarks do Grok 4.20 (Non-Reasoning) and Mercury 2.5 share?

2 benchmarks have published results for both models. Grok 4.20 (Non-Reasoning) has 46 scored results on Noometry and Mercury 2.5 has 2.