GPT-5 CodexvsMuse Spark 1.3 Contributor
Muse Spark 1.3 Contributor is the newer model, released after GPT-5 Codex.
| Spec | GPT-5 Codex | Muse Spark 1.3 Contributor |
|---|---|---|
| Input price | — | $0.1/M tokens |
| Output price | — | $0.2/M tokens |
| Context window | — | 1.0M tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Sep 2025 | Sep 2026 |
Our Verdict
GPT-5 Codex
Muse Spark 1.3 Contributor
Not enough votes to call it. On the specs, nothing separates them.
Too close to call
Reviewing agent-written code?See a Brief PR report
API pricing
Cost per 1M tokens
GPT-5 Codex
Input
—
Output
—
Muse Spark 1.3 Contributor
Input
$0.10
Output
$0.20
Where to run it
1 host
GPT-5 Codex
No hosts listed on OpenRouter.
Muse Spark 1.3 Contributor1 host
Per million tokens. Prices and uptime via OpenRouter, checked 12 Sep 2026.
Writing DNA
Style Comparison
Similarity
53%
GPT-5 Codex uses 14.6x more emoji
GPT-5 Codex
Muse Spark 1.3 Contributor
64%Vocabulary58%
17wSentence Length13w
0.38Hedging0.27
2.3Bold2.8
3.5Lists2.3
0.15Emoji0.00
0.49Headings0.44
0.05Transitions0.02
Based on 13 + 27 text responses
Research
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FAQ
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