Muse Spark 1.1 leads on 1 of 1 shared benchmark; GPT-5.3-Codex leads on 0.
Muse Spark 1.1 is about 2.4× cheaper on a blended 3:1 input/output basis ($2.00 vs $4.81 per 1M tokens).
Muse Spark 1.1 has the larger context window (1,048,576 tokens vs 400,000 tokens).
Choose Muse Spark 1.1 if…
- • you want the model leading more of the 1 shared benchmark
- • lower blended API cost matters for your workload
- • you work with longer documents, transcripts, or codebases
Choose GPT-5.3-Codex if…
- • your own prompt tests favor its output; the catalog data shows no unique advantage
This verdict uses shared benchmark and capability data shown below. For text-output models, it also compares token pricing and context windows. Missing data is not treated as a win.
| Muse Spark 1.1 | GPT-5.3-Codex | |
|---|---|---|
| Context & model facts | ||
| Provider | Meta | OpenAI |
| Context Length | 1,048,576 tokens | 400,000 tokens |
| Maximum Output | — | 128,000 tokens |
| Added to Catalog | Jul 16, 2026 | Feb 24, 2026 |
| License | Proprietary | Proprietary |
| Capabilities | ||
| Reasoning | ||
| Vision | ||
| Image Generation | ||
| Video Generation | ||
| API pricing | ||
| Input (per 1M tokens) | $1.25 | $1.75 |
| Output (per 1M tokens) | $4.25 | $14.00 |
| Performance benchmarks | ||
Human preference score | 1487 ±6 | — |
Human preference score for code and web development | 1536 | 1369 |
Data sources
- Arena AI leaderboard
- Writingmate model catalog (pricing, limits, and availability)
Catalog data last updated Jul 16, 2026. Arena data last refreshed Aug 9, 2026.
Comparing Muse Spark 1.1 from Meta with GPT-5.3-Codex from OpenAI? Instead of managing separate API keys and subscriptions, get both with Writingmate.
| Plan | Price | Muse Spark 1.1 | GPT-5.3-Codex | AI Images | AI Video |
|---|---|---|---|---|---|
Meta AI Model API access | Varies | Imagine (limited) | — | ||
ChatGPT Plus GPT-5.2 (limited) | $20/mo | DALL-E | Sora (limited) | ||
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