# GPT-5.3 Chat vs Grok 4.20 (Non-Reasoning)

> Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 42.8 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-chat-vs-grok-4-20
- Last updated: 2026-10-12
- Shared benchmarks: 18

## Summary

- They share 18 benchmarks with published results for both. GPT-5.3 Chat scores higher in 0 categories and Grok 4.20 (Non-Reasoning) in 8 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 28.5.
- Grok 4.20 (Non-Reasoning) is cheaper at $1.25 / $2.50 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Chat.
- Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 128K.

## Snapshot

| | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 42.8 | 48.6 |
| Rank | 109 | 54 |
| Context | 128K | 1M |
| Input $/M | $1.75 | $1.25 |
| Output $/M | $14 | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Chat: 41.4 (#124)
- Grok 4.20 (Non-Reasoning): 42.1 (#112)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Coding | 1408 | 1459 |
| LMArena WebDev | — | 1375 |
| WeirdML | — | 52.3% |
| ALE-Bench | — | 1,150 |

## Agentic & Tool Use

- GPT-5.3 Chat: —
- Grok 4.20 (Non-Reasoning): 34.4 (#46)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Terminal-Bench | — | 57.3% |
| τ²-bench Banking | — | 18% |
| LMArena Search | — | 1189 |
| Vending-Bench 2 | — | 4,663 |

## Reasoning

- GPT-5.3 Chat: 28.5 (#102)
- Grok 4.20 (Non-Reasoning): 52.3 (#32)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1451 |
| 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% |
| DTBench | — | 90.1% |
| LMCA | — | 38.7% |
| Epoch Capabilities Index | — | 151.98 |
| ForecastBench | — | 61.4 |

## Math

- GPT-5.3 Chat: 38.2 (#142)
- Grok 4.20 (Non-Reasoning): 48.2 (#65)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Math | 1389 | 1455 |
| FrontierMath (Tiers 1-3) | — | 44.9% |
| FrontierMath Tier 4 | — | 17.1% |
| OTIS Mock AIME 2024-2025 | — | 92.2% |
| ProofBench | — | 14% |

## Knowledge

- GPT-5.3 Chat: 38.8 (#140)
- Grok 4.20 (Non-Reasoning): 52.8 (#60)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Expert | 1397 | 1439 |
| GPQA Diamond | — | 89.3% |
| SimpleQA Verified | — | 30.2% |

## Multimodal

- GPT-5.3 Chat: —
- Grok 4.20 (Non-Reasoning): 33.3 (#98)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Vision | — | 1263 |
| Blueprint-Bench 2 | — | 0% |
| LMArena Document | — | 1416 |

## Multilingual

- GPT-5.3 Chat: 50.3 (#124)
- Grok 4.20 (Non-Reasoning): 54.5 (#40)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Non-English | 1382 | 1441 |
| LMArena Chinese | 1432 | 1481 |
| LMArena French | 1397 | 1476 |
| LMArena German | 1384 | 1465 |
| LMArena Japanese | 1352 | 1449 |
| LMArena Korean | 1346 | 1417 |
| LMArena Russian | 1400 | 1458 |
| LMArena Spanish | 1371 | 1443 |

## Instruction Following

- GPT-5.3 Chat: 72.8 (#129)
- Grok 4.20 (Non-Reasoning): 74.8 (#83)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Instruction Following | 1378 | 1420 |

## Long Context

- GPT-5.3 Chat: 42.6 (#120)
- Grok 4.20 (Non-Reasoning): 45.5 (#34)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Longer Query | 1396 | 1437 |
| CL-bench | — | 22.2% |
| CL-bench Life | — | 11.9% |

## Writing & Preference

- GPT-5.3 Chat: 63.1 (#68)
- Grok 4.20 (Non-Reasoning): 65.7 (#44)

| Benchmark | GPT-5.3 Chat | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Text | 1389 | 1451 |
| LMArena Creative Writing | 1355 | 1438 |
| EQ-Bench Creative Writing | 1690 | 1574 |
| LMArena Multi-Turn | 1412 | 1456 |

## FAQ

### Is GPT-5.3 Chat better than Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 42.8 on the Noometry Index.

### Which is cheaper, GPT-5.3 Chat or Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; GPT-5.3 Chat lists at $1.75 and $14.

### Is GPT-5.3 Chat or Grok 4.20 (Non-Reasoning) better for coding?

They score almost the same on coding (41.4 vs 42.1); test both on your own repository before choosing.

### Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 128K.

### How many benchmarks do GPT-5.3 Chat and Grok 4.20 (Non-Reasoning) share?

18 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.