# GPT-5.3 Codex vs Muse Spark

> Side-by-side benchmark comparison for GPT-5.3 Codex and Muse Spark across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-3-codex-vs-muse-spark
- Last updated: October 17, 2026

- Shared sourced benchmarks: 5
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick GPT-5.3 Codex if you want the stronger benchmark profile. Muse Spark only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-5.3 Codex leads overall 60.48 to 60.47.
- The clearest category separation is in reasoning, where the averages are 83.1 for GPT-5.3 Codex and 57.1 for Muse Spark.
- The biggest single benchmark swing is Vibe Code Bench in Coding, with scores of 61.77% and 19.67%.
- GPT-5.3 Codex also has the larger context window at 400K.

## Model Snapshot

| Property | GPT-5.3 Codex | Muse Spark |
|----------|----------|----------|
| Creator | OpenAI | Meta |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 400K | 262K |
| Overall Score | 60.48 | 60.47 |
| Benchmarks Covered | 11 | 25 |
| Pricing (input/output) | $1.75 / $14.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Directional only
- GPT-5.3 Codex public-lane score: 55.5 (Estimated · #41/128)
- Muse Spark public-lane score: 51 (Supported · #46/128)

| Benchmark | GPT-5.3 Codex | Muse Spark | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 77.3% | 59% | GPT-5.3 Codex |
| OSWorld-Verified | 64.7% | Coming soon | Coming soon |
| Gert Labs | 57.47% | Coming soon | Coming soon |
| JobBench | 33.7% | Coming soon | Coming soon |
| τ²-bench results | Coming soon | 91.5% | Coming soon |
| DeepSearchQA | Coming soon | 74.8% | Coming soon |
| CyberGym | Coming soon | 43.5% | Coming soon |
| Claw-Eval | Coming soon | 63.8% | Coming soon |

### Coding

- Winner: GPT-5.3 Codex
- GPT-5.3 Codex public-lane score: 53.5 (Supported · #35/150)
- Muse Spark public-lane score: 49.9 (Supported · #44/150)

| Benchmark | GPT-5.3 Codex | Muse Spark | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85% | 77.4% | GPT-5.3 Codex |
| SWE-bench Pro | 56.8% | 52.4% | GPT-5.3 Codex |
| SWE-Rebench | 58.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| Vibe Code Bench | 61.77% | 19.67% | GPT-5.3 Codex |
| LiveCodeBench (Vals) | 87.3% | Coming soon | Coming soon |
| SWE-bench (Vals) | 78.0% | 74.4% | GPT-5.3 Codex |
| LiveCodeBench Pro | Coming soon | 80.0% | Coming soon |

### Reasoning

- Winner: Not comparable
- GPT-5.3 Codex public-lane score: 83.1 (Unranked · 2 rankable rows)
- Muse Spark public-lane score: 57.1 (Unranked · 3 rankable rows)

| Benchmark | GPT-5.3 Codex | Muse Spark | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 42.5% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- GPT-5.3 Codex public-lane score: 80.1 (Unranked · 1 rankable row)
- Muse Spark public-lane score: 84.4 (#12/54)

| Benchmark | GPT-5.3 Codex | Muse Spark | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 86.4% | Coming soon |
| MMMU-Pro | Coming soon | 80.4% | Coming soon |
| ERQA | Coming soon | 64.7% | Coming soon |
| SimpleVQA | Coming soon | 71.3% | Coming soon |
| ScreenSpot Pro | Coming soon | 84.1% | Coming soon |
| ZeroBench | Coming soon | 33.0% | Coming soon |
| MedXpertQA (MM) | Coming soon | 78.4% | Coming soon |

### Knowledge

- Winner: Directional only
- GPT-5.3 Codex public-lane score: 65.4 (Estimated · #33/184)
- Muse Spark public-lane score: 62.5 (Supported · #44/184)

| Benchmark | GPT-5.3 Codex | Muse Spark | Winner |
|-----------|-----------|-----------|--------|
| GPQA-D | Coming soon | 89.5% | Coming soon |
| HLE | Coming soon | 50.4% | Coming soon |
| HLE w/o tools | Coming soon | 42.8% | Coming soon |
| HealthBench Hard | Coming soon | 42.8% | Coming soon |
| MedXpertQA (Text) | Coming soon | 52.6% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 89.6% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 87.3% | Coming soon |

### Instruction Following

- Winner: Directional only
- GPT-5.3 Codex public-lane score: 92.6 (#18/148)
- Muse Spark public-lane score: 93.3 (#10/148)

## FAQ

### Which is better overall, GPT-5.3 Codex or Muse Spark?

GPT-5.3 Codex is ahead overall on BenchLM right now.

### Where is the biggest gap between GPT-5.3 Codex and Muse Spark?

The widest category gap is in reasoning, where the averages are 83.1 for GPT-5.3 Codex and 57.1 for Muse Spark.

### How many benchmarks does GPT-5.3 Codex cover on BenchLM?

GPT-5.3 Codex currently has 11 sourced benchmark scores on BenchLM.

### How many benchmarks does Muse Spark cover on BenchLM?

Muse Spark currently has 25 sourced benchmark scores on BenchLM.

## Related Comparisons

- [GPT-5.3 Codex vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-vs-gpt-5-3-codex-spark)
- [Muse Spark vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-spark-vs-muse-spark)
- [GPT-5.3 Codex vs Muse Spark 1.1](/compare/gpt-5-3-codex-vs-muse-spark-1-1)
- [Muse Spark vs Muse Spark 1.1](/compare/muse-spark-vs-muse-spark-1-1)

## Explore More

- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Muse Spark profile](/models/muse-spark)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)