# GPT-5.3 Codex vs Muse Spark

> Muse Spark is the stronger model overall, scoring 50.6 to 45.8 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-3-codex-vs-muse-spark
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. GPT-5.3 Codex scores higher in 1 category and Muse Spark in 0 categories; one gap is clear of the uncertainty.

## Snapshot

| | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 45.8 | 50.6 |
| Rank | 69 | 46 |
| Context | 400K | — |
| Input $/M | $1.75 | — |
| Output $/M | $14 | — |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.3 Codex: 48.6 (#56)
- Muse Spark: 46.2 (#69)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| SWE-bench Verified | 74.8% | — |
| LMArena WebDev | 1409 | — |
| SciCode | — | 51.5% |
| WeirdML | 79.3% | — |
| LMArena Coding | — | 1481 |
| ALE-Bench | 1,655 | — |

## Agentic & Tool Use

- GPT-5.3 Codex: 48.0 (#9)
- Muse Spark: —

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |

## Reasoning

- GPT-5.3 Codex: —
- Muse Spark: 35.9 (#67)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| Epoch Capabilities Index | 156.77 | 152.04 |
| CritPt | — | 11.3% |
| LMArena Hard Prompts | — | 1474 |

## Math

- GPT-5.3 Codex: —
- Muse Spark: 47.8 (#66)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 88.9% |
| ProofBench | — | 17% |
| LMArena Math | — | 1455 |
| FrontierMath (Feb 2025 set) | — | 39% |
| FrontierMath Tier 4 (v1) | — | 14.6% |

## Knowledge

- GPT-5.3 Codex: —
- Muse Spark: 65.7 (#13)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| GPQA Diamond | — | 89.8% |
| Humanity's Last Exam | — | 40.6% |
| LMArena Expert | — | 1457 |

## Multimodal

- GPT-5.3 Codex: —
- Muse Spark: 43.4 (#24)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| LMArena Vision | — | 1306 |
| LMArena Document | — | 1444 |

## Multilingual

- GPT-5.3 Codex: —
- Muse Spark: 56.1 (#24)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| LMArena Non-English | — | 1464 |
| LMArena Chinese | — | 1509 |
| LMArena French | — | 1497 |
| LMArena German | — | 1497 |
| LMArena Korean | — | 1459 |
| LMArena Russian | — | 1466 |
| LMArena Spanish | — | 1472 |

## Instruction Following

- GPT-5.3 Codex: —
- Muse Spark: 75.9 (#51)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| LMArena Instruction Following | — | 1442 |

## Long Context

- GPT-5.3 Codex: —
- Muse Spark: 44.4 (#69)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| LMArena Longer Query | — | 1451 |

## Writing & Preference

- GPT-5.3 Codex: —
- Muse Spark: 66.0 (#39)

| Benchmark | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| LMArena Text | — | 1474 |
| LMArena Creative Writing | — | 1459 |
| LMArena Multi-Turn | — | 1477 |

## FAQ

### Is GPT-5.3 Codex better than Muse Spark?

Muse Spark is the stronger model overall, scoring 50.6 to 45.8 on the Noometry Index.

### Is GPT-5.3 Codex or Muse Spark better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 46.2 in the Noometry coding category.

### How many benchmarks do GPT-5.3 Codex and Muse Spark share?

1 benchmark has published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Muse Spark has 27.