# GPT-5-Codex vs Grok 4.20 Multi-Agent

> Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 37.3 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-codex-vs-grok-4-20-multi-agent
- Last updated: 2026-10-10
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Grok 4.20 Multi-Agent leads 42.4 to 30.0.
- Grok 4.20 Multi-Agent is cheaper at $1.25 / $2.50 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- Grok 4.20 Multi-Agent accepts more context: 1M tokens versus 400K.

## Snapshot

| | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 37.3 | 45.5 |
| Rank | 190 | 62 |
| Context | 400K | 1M |
| Input $/M | $1.25 | $1.25 |
| Output $/M | $10 | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5-Codex: 41.9 (#100)
- Grok 4.20 Multi-Agent: 42.4 (#91)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| WeirdML | 54.5% | — |
| LMArena Coding | — | 1458 |

## Agentic & Tool Use

- GPT-5-Codex: 30.8 (#66)
- Grok 4.20 Multi-Agent: —

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| Terminal-Bench | 44.3% | — |
| LMArena Search | — | 1204 |

## Reasoning

- GPT-5-Codex: 30.0 (#80)
- Grok 4.20 Multi-Agent: 42.4 (#44)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| NYT Connections (extended) | — | 89.6% |
| LMArena Hard Prompts | — | 1448 |

## Math

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 36.6 (#106)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Math | — | 1441 |

## Knowledge

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 39.7 (#116)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Expert | — | 1445 |

## Multimodal

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 39.8 (#44)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Vision | — | 1259 |

## Multilingual

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 54.6 (#40)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Non-English | — | 1440 |
| LMArena Chinese | — | 1475 |
| LMArena French | — | 1467 |
| LMArena German | — | 1456 |
| LMArena Japanese | — | 1405 |
| LMArena Korean | — | 1416 |
| LMArena Russian | — | 1457 |
| LMArena Spanish | — | 1447 |

## Instruction Following

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 75.0 (#80)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Instruction Following | — | 1420 |

## Long Context

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 43.7 (#84)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Longer Query | — | 1430 |

## Writing & Preference

- GPT-5-Codex: —
- Grok 4.20 Multi-Agent: 64.1 (#57)

| Benchmark | GPT-5-Codex | Grok 4.20 Multi-Agent |
|---|---|---|
| LMArena Text | — | 1450 |
| LMArena Creative Writing | — | 1435 |
| LMArena Multi-Turn | — | 1451 |

## FAQ

### Is GPT-5-Codex better than Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 37.3 on the Noometry Index.

### Which is cheaper, GPT-5-Codex or Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is GPT-5-Codex or Grok 4.20 Multi-Agent better for coding?

They score almost the same on coding (41.9 vs 42.4); test both on your own repository before choosing.

### Which has the bigger context window?

Grok 4.20 Multi-Agent does, with 1M tokens against 400K.

### How many benchmarks do GPT-5-Codex and Grok 4.20 Multi-Agent share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Grok 4.20 Multi-Agent has 20.