# GPT-5-Codex vs Muse Spark 1.3

> Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-codex-vs-muse-spark-1-3
- Last updated: 2026-10-11
- Shared benchmarks: 0

## Summary

- The widest gap is in reasoning, where Muse Spark 1.3 leads 54.0 to 30.9.
- Muse Spark 1.3 is cheaper at $1.25 / $4.25 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
- Muse Spark 1.3 accepts more context: 1.05M tokens versus 400K.

## Snapshot

| | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 37.9 | 54.8 |
| Rank | 192 | 27 |
| Context | 400K | 1.05M |
| Input $/M | $1.25 | $1.25 |
| Output $/M | $10 | $4.25 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5-Codex: 42.4 (#103)
- Muse Spark 1.3: 56.6 (#21)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| CursorBench | — | 41.6% |
| LMArena WebDev | — | 1657 |
| SciCode | — | 59.7% |
| WeirdML | 54.5% | — |
| LMArena Coding | — | 1514 |

## Agentic & Tool Use

- GPT-5-Codex: 31.0 (#72)
- Muse Spark 1.3: 38.6 (#30)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| Terminal-Bench | 44.3% | — |
| APEX-Agents | — | 57.8% |
| GDP.pdf | — | 27.6% |

## Reasoning

- GPT-5-Codex: 30.9 (#83)
- Muse Spark 1.3: 54.0 (#27)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | — |
| NYT Connections (extended) | — | 85.1% |
| CritPt | — | 26% |
| Chess Puzzles | — | 38% |
| LMArena Hard Prompts | — | 1503 |
| Mystery Game Puzzles | — | 25% |
| DTBench | — | 96.5% |
| LMCA | — | 53.9% |
| Bench to the Future 3 | — | 0.14 |
| Epoch Capabilities Index | — | 156.75 |

## Math

- GPT-5-Codex: —
- Muse Spark 1.3: 73.1 (#21)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 74.4% |
| FrontierMath Tier 4 | — | 46.3% |
| OTIS Mock AIME 2024-2025 | — | 99.2% |
| ProofBench | — | 58% |
| LMArena Math | — | 1494 |

## Knowledge

- GPT-5-Codex: —
- Muse Spark 1.3: 42.6 (#95)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Expert | — | 1516 |

## Multimodal

- GPT-5-Codex: —
- Muse Spark 1.3: 43.7 (#22)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Vision | — | 1309 |
| LMArena Document | — | 1471 |

## Multilingual

- GPT-5-Codex: —
- Muse Spark 1.3: 57.4 (#8)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Non-English | — | 1481 |
| LMArena Chinese | — | 1529 |
| LMArena French | — | 1524 |
| LMArena German | — | 1515 |
| LMArena Japanese | — | 1474 |
| LMArena Korean | — | 1501 |
| LMArena Russian | — | 1490 |
| LMArena Spanish | — | 1490 |

## Instruction Following

- GPT-5-Codex: —
- Muse Spark 1.3: 77.5 (#22)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Instruction Following | — | 1477 |

## Long Context

- GPT-5-Codex: —
- Muse Spark 1.3: 45.6 (#32)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Longer Query | — | 1488 |

## Writing & Preference

- GPT-5-Codex: —
- Muse Spark 1.3: 73.6 (#9)

| Benchmark | GPT-5-Codex | Muse Spark 1.3 |
|---|---|---|
| LMArena Text | — | 1490 |
| LMArena Creative Writing | — | 1455 |
| EQ-Bench Creative Writing | — | 1906 |
| LMArena Multi-Turn | — | 1482 |

## FAQ

### Is GPT-5-Codex better than Muse Spark 1.3?

Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

### Which is cheaper, GPT-5-Codex or Muse Spark 1.3?

Muse Spark 1.3 is cheaper. It lists at $1.25 per million input tokens and $4.25 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

### Is GPT-5-Codex or Muse Spark 1.3 better for coding?

Muse Spark 1.3 scores higher on coding benchmarks: 56.6 versus 42.4 in the Noometry coding category.

### Which has the bigger context window?

Muse Spark 1.3 does, with 1.05M tokens against 400K.

### How many benchmarks do GPT-5-Codex and Muse Spark 1.3 share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Muse Spark 1.3 has 37.