# GPT-4o mini vs Grok 4.5

> Grok 4.5 is the stronger model overall, scoring 55.0 to 25.4 on the Noometry Index. GPT-4o mini costs 11× less per token, which makes it the better buy when Grok 4.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gpt-4o-mini-vs-grok-4-5
- Last updated: 2026-10-10
- Shared benchmarks: 31

## Summary

- They share 31 benchmarks with published results for both. GPT-4o mini scores higher in 0 categories and Grok 4.5 in 10 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Grok 4.5 leads 60.7 to 9.9.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 6.9% for GPT-4o mini and 97.8% for Grok 4.5.
- GPT-4o mini is cheaper at $0.15 / $0.60 per million input/output tokens, against $2 / $6 for Grok 4.5.
- Grok 4.5 accepts more context: 500K tokens versus 128K.

## Snapshot

| | GPT-4o mini | Grok 4.5 |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 25.4 | 55.0 |
| Rank | 337 | 22 |
| Context | 128K | 500K |
| Input $/M | $0.15 | $2 |
| Output $/M | $0.60 | $6 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-4o mini: 21.6 (#330)
- Grok 4.5: 51.7 (#34)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| WeirdML | 11.8% | 46.4% |
| LMArena Coding | 1290 | 1473 |
| DeepSWE | — | 53.8% |
| FrontierCode | — | 42.4% |
| Aider Polyglot | 3.6% | — |
| LMArena WebDev | — | 1552 |
| SciCode | — | 54.1% |
| BigCodeBench Instruct | 46.1% | — |
| LiveBench Coding | 43.1% | — |
| BigCodeBench Complete | 57.4% | — |
| ALE-Bench | — | 1,309 |
| HumanEval+ | 83.5% | — |
| MBPP+ | 72.2% | — |

## Agentic & Tool Use

- GPT-4o mini: 27.2 (#95)
- Grok 4.5: 44.4 (#15)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| APEX-Agents | — | 56.2% |
| τ²-bench Banking | — | 47.9% |
| PostTrainBench | — | 23.4% |
| BALROG | 17.4% | — |
| GBAEval | — | 65.4% |
| GDP.pdf | — | 14% |
| LMArena Search | — | 1213 |
| Vending-Bench 2 | — | 3,887 |

## Reasoning

- GPT-4o mini: 8.7 (#343)
- Grok 4.5: 56.0 (#23)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| ARC-AGI-2 | 0% | 52.6% |
| SimpleBench | 10.7% | 70% |
| Kagi LLM Benchmark | 28.8% | 83.5% |
| Chess Puzzles | 0% | 36% |
| LMArena Hard Prompts | 1267 | 1462 |
| DTBench | 54.4% | 96.5% |
| LMCA | 10.4% | 45.2% |
| Epoch Capabilities Index | 126.56 | 154.02 |
| NYT Connections (extended) | — | 79.9% |
| ARC-AGI-1 | — | 87.2% |
| CritPt | — | 15.4% |
| LiveBench Reasoning | 32.8% | — |
| Mystery Game Puzzles | 12% | — |
| LiveBench Data Analysis | 50% | — |
| Surface Evolver Bench | — | 74.4% |
| LiveBench | 41.3% | — |
| PIQA | 88.7% | — |

## Math

- GPT-4o mini: 9.9 (#307)
- Grok 4.5: 60.7 (#29)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 0.7% | 57.2% |
| OTIS Mock AIME 2024-2025 | 6.9% | 97.8% |
| LMArena Math | 1267 | 1457 |
| FrontierMath Tier 4 | — | 24.4% |
| ProofBench | — | 31% |
| Omni-MATH | 28% | — |
| LiveBench Math | 36.3% | — |
| MATH Level 5 | 52.6% | — |
| GSM8K | 91.3% | — |

## Knowledge

- GPT-4o mini: 17.7 (#279)
- Grok 4.5: 62.3 (#21)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| GPQA Diamond | 37.7% | 93.4% |
| SimpleQA Verified | 8.3% | 48.3% |
| LMArena Expert | 1235 | 1466 |
| MMLU-Pro | 60.3% | — |
| Confabulations | 37.2% | — |
| GPQA (HELM) | 36.8% | — |
| BoolQ | 88.7% | — |
| MMLU | 81.8% | — |

## Multimodal

- GPT-4o mini: 25.3 (#117)
- Grok 4.5: 37.8 (#63)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| LMArena Vision | 1066 | 1287 |
| Video-MME | 64.8% | — |
| GeoBench | 64% | — |
| VPCT | 34% | — |
| Blueprint-Bench 2 | — | 27.3% |
| Furniture Assembly | — | 22.5% |
| LMArena Document | — | 1452 |

## Multilingual

- GPT-4o mini: 42.2 (#194)
- Grok 4.5: 54.5 (#43)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| LMArena Non-English | 1266 | 1439 |
| LMArena Chinese | 1264 | 1497 |
| LMArena French | 1296 | 1458 |
| LMArena German | 1272 | 1448 |
| LMArena Japanese | 1216 | 1425 |
| LMArena Korean | 1195 | 1402 |
| LMArena Russian | 1275 | 1447 |
| LMArena Spanish | 1276 | 1452 |

## Instruction Following

- GPT-4o mini: 62.1 (#234)
- Grok 4.5: 76.3 (#45)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| LMArena Instruction Following | 1259 | 1446 |
| LiveBench Instruction Following | 56.8% | — |
| IFEval | 78.2% | — |

## Long Context

- GPT-4o mini: 39.1 (#181)
- Grok 4.5: 44.8 (#54)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| LMArena Longer Query | 1289 | 1463 |

## Writing & Preference

- GPT-4o mini: 39.7 (#243)
- Grok 4.5: 65.9 (#40)

| Benchmark | GPT-4o mini | Grok 4.5 |
|---|---|---|
| LMArena Text | 1286 | 1448 |
| LMArena Creative Writing | 1268 | 1442 |
| EQ-Bench Creative Writing | 873 | 1579 |
| LMArena Multi-Turn | 1285 | 1457 |
| Short-Story Creative Writing | 67.2% | — |
| WildBench | 79.1% | — |
| LiveBench Language | 28.6% | — |

## FAQ

### Is GPT-4o mini better than Grok 4.5?

Grok 4.5 is the stronger model overall, scoring 55.0 to 25.4 on the Noometry Index. GPT-4o mini costs 11× less per token, which makes it the better buy when Grok 4.5's lead doesn't matter for your workload.

### Which is cheaper, GPT-4o mini or Grok 4.5?

GPT-4o mini is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Grok 4.5 lists at $2 and $6.

### Is GPT-4o mini or Grok 4.5 better for coding?

Grok 4.5 scores higher on coding benchmarks: 51.7 versus 21.6 in the Noometry coding category.

### Which has the bigger context window?

Grok 4.5 does, with 500K tokens against 128K.

### How many benchmarks do GPT-4o mini and Grok 4.5 share?

31 benchmarks have published results for both models. GPT-4o mini has 60 scored results on Noometry and Grok 4.5 has 52.