GPT-5.3 Codex vs Muse Spark
GPT-5.3 Codex (OpenAI) and Muse Spark (Meta AI) compared on benchmarks, pricing, context window, and use-case rankings.
- GPT-5.3 Codex leads on overall intelligence (ECI 156 vs 154).
- Muse Spark ranks higher for coding (79th vs 67th percentile).
| Attribute | GPT-5.3 Codex | Muse Spark |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 156 | 154 |
| Coding | 67 | 79 |
| Math | — | 66 |
| Reasoning & Knowledge | 87 | 84 |
| Agentic & Tools | 67 | 64 |
| Specifications | ||
| Developer | OpenAI | Meta AI |
| Family | GPT | — |
| Released | Feb 5, 2026 | Apr 8, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 400K | — |
| Price — $/M input | $1.75 | — |
| Price — $/M output | $14.00 | — |
| Inputs | text, image, file | — |
| Outputs | text | — |
| Benchmarks | ||
| APEX | 32% | — |
| GPQA Diamond | 92% | 90% |
| Humanity's Last Exam | 40% | 41% |
| METR task horizon | 5.8 h | — |
| SciCode | 53% | 52% |
| SWE-bench Verified | 75% | — |
| Terminal-Bench | 78% | — |
| WebDev Arena | 1407 | 1513 |
| WeirdML | 79% | — |
| τ²-bench | 86% | 92% |
| AIME 2024/2025 | — | 89% |
| FrontierMath | — | 39% |
| FrontierMath Tier 4 | — | 15% |
| SimpleQA Verified | — | 66% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is GPT-5.3 Codex better than Muse Spark?
On Epoch AI's Capabilities Index, GPT-5.3 Codex scores higher (156) than Muse Spark (154). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is better for coding, GPT-5.3 Codex or Muse Spark?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Muse Spark ranks higher — 79th vs 67th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.