# GPT-5.3 Codex vs Muse Spark 1.1

> Side-by-side benchmark comparison for GPT-5.3 Codex and Muse Spark 1.1 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-3-codex-vs-muse-spark-1-1
- Last updated: October 7, 2026

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

## Quick Verdict

Pick Muse Spark 1.1 if you want the stronger benchmark profile. GPT-5.3 Codex only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Muse Spark 1.1 leads overall 65.95 to 60.87.
- The clearest category separation is in reasoning, where the averages are 79.6 for GPT-5.3 Codex and 75.7 for Muse Spark 1.1.
- The biggest single benchmark swing is JobBench in Agentic, with scores of 33.7% and 54.7%.
- Muse Spark 1.1 also has the larger context window at 1M.

## Model Snapshot

| Property | GPT-5.3 Codex | Muse Spark 1.1 |
|----------|----------|----------|
| Creator | OpenAI | Meta |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 400K | 1M |
| Overall Score | 60.87 | 65.95 |
| Benchmarks Covered | 10 | 26 |
| Pricing (input/output) | $1.75 / $14.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Directional only
- GPT-5.3 Codex public-lane score: 55.4 (Estimated · #35/122)
- Muse Spark 1.1 public-lane score: 56.9 (Supported · #32/122)

| Benchmark | GPT-5.3 Codex | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 77.3% | Coming soon | Coming soon |
| OSWorld-Verified | 64.7% | 80.8% | Muse Spark 1.1 |
| Gert Labs | 57.47% | Coming soon | Coming soon |
| JobBench | 33.7% | 54.7% | Muse Spark 1.1 |
| Terminal-Bench 2.1 | Coming soon | 80.0% | Coming soon |
| MCP Atlas | Coming soon | 88.1% | Coming soon |
| Toolathlon | Coming soon | 75.6% | Coming soon |
| WebArena-Verified | Coming soon | 69% | Coming soon |
| DeepSearchQA | Coming soon | 84.9% | Coming soon |
| CyberGym | Coming soon | 59.0% | Coming soon |
| Finance Agent v2 | Coming soon | 57.2% | Coming soon |
| deepSwe | Coming soon | 53.3% | Coming soon |
| OSWorld 2.0 | Coming soon | 14.2% | Coming soon |
| Cybench | Coming soon | 92.9% | Coming soon |
| ExploitGym | Coming soon | 0.8% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 69.3% | Coming soon |

### Coding

- Winner: GPT-5.3 Codex
- GPT-5.3 Codex public-lane score: 55.9 (Supported · #30/146)
- Muse Spark 1.1 public-lane score: 54.2 (Supported · #35/146)

| Benchmark | GPT-5.3 Codex | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85% | Coming soon | Coming soon |
| SWE-bench Pro | 56.8% | 61.5% | Muse Spark 1.1 |
| SWE-Rebench | 58.2% | Coming soon | Coming soon |
| Vibe Code Bench | 61.77% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.3% | 85.9% | GPT-5.3 Codex |
| SWE-bench (Vals) | 78.0% | 82.0% | Muse Spark 1.1 |
| Terminal-Bench 2.1 | Coming soon | 80.0% | Coming soon |

### Reasoning

- Winner: Not comparable
- GPT-5.3 Codex public-lane score: 79.6 (Unranked · 2 rankable rows)
- Muse Spark 1.1 public-lane score: 75.7 (Unranked · 3 rankable rows)

| Benchmark | GPT-5.3 Codex | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| MRCR 1M | Coming soon | 54.1% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- GPT-5.3 Codex public-lane score: 76.7 (Unranked · 1 rankable row)
- Muse Spark 1.1 public-lane score: 78.3 (Unranked · 2 rankable rows)

| Benchmark | GPT-5.3 Codex | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 88.4% | Coming soon |
| BabyVision | Coming soon | 76.3% | Coming soon |

### Knowledge

- Winner: Directional only
- GPT-5.3 Codex public-lane score: 64.4 (Estimated · #27/174)
- Muse Spark 1.1 public-lane score: 66.7 (Supported · #21/174)

| Benchmark | GPT-5.3 Codex | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| HLE | Coming soon | 62.1% | Coming soon |
| HLE w/o tools | Coming soon | 52.2% | Coming soon |
| HealthBench Professional | Coming soon | 59.3% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 91.2% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 88.7% | Coming soon |

### Instruction Following

- Winner: Not comparable
- GPT-5.3 Codex public-lane score: 91.2 (#14/125)
- Muse Spark 1.1 public-lane score: Coming soon

## FAQ

### Which is better overall, GPT-5.3 Codex or Muse Spark 1.1?

Muse Spark 1.1 is ahead overall on BenchLM right now.

### Where is the biggest gap between GPT-5.3 Codex and Muse Spark 1.1?

The widest category gap is in reasoning, where the averages are 79.6 for GPT-5.3 Codex and 75.7 for Muse Spark 1.1.

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

GPT-5.3 Codex currently has 10 sourced benchmark scores on BenchLM.

### How many benchmarks does Muse Spark 1.1 cover on BenchLM?

Muse Spark 1.1 currently has 26 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 1.1 vs GPT-5.3-Codex-Spark](/compare/gpt-5-3-codex-spark-vs-muse-spark-1-1)
- [GPT-5.3 Codex vs Muse Spark 1.2](/compare/gpt-5-3-codex-vs-muse-spark-1-2)
- [Muse Spark 1.1 vs Muse Spark 1.2](/compare/muse-spark-1-1-vs-muse-spark-1-2)

## Explore More

- [GPT-5.3 Codex profile](/models/gpt-5-3-codex)
- [Muse Spark 1.1 profile](/models/muse-spark-1-1)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)