GPT-5.4 mini vs Muse Spark Open
Price and specs side by side · USD per 1M tokens · verified 2026-10-23
// side by side
| metric | GPT-5.4 mini | Muse Spark Open |
|---|
| input / 1M | $0.75 | $1.25 |
| output / 1M | $4.50 | $4.25 |
| blended (3:1) | $1.6875 | $2.00 |
| cache read / 1M | $0.075 | $0.15 |
| context | 400K | 1.05M |
| max output | 128K | 131.1K |
| input types | text · image | text · image |
| reasoning | yes | yes |
| tool calling | yes | yes |
| structured output | yes | yes |
| open weights | no | yes |
| released | 2026-03-17 | 2026-10-15 |
| knowledge cutoff | 2025-08-31 | 2026-01-04 |
| lab | OpenAI | Meta |
// monthly cost scenarios
| workload | tokens in / out | GPT-5.4 mini | Muse Spark Open |
|---|
| Chatbot | 10M / 2M | $16.50 | $21.00 |
| RAG app | 50M / 5M | $60.00 | $83.75 |
| Coding agent | 20M / 10M | $60.00 | $67.50 |
// verdict
- GPT-5.4 mini is 15.6% cheaper than Muse Spark Open on a blended 3:1 input/output basis.
- Muse Spark Open has the larger context window (1.05M vs 400K tokens).
- Chatbot (10M input / 2M output tokens per month): GPT-5.4 mini costs $16.50 vs $21.00 for Muse Spark Open, saving $4.50 per month.
- RAG app (50M input / 5M output tokens per month): GPT-5.4 mini costs $60.00 vs $83.75 for Muse Spark Open, saving $23.75 per month.
- Coding agent (20M input / 10M output tokens per month): GPT-5.4 mini costs $60.00 vs $67.50 for Muse Spark Open, saving $7.50 per month.
// GPT-5.4 mini or Muse Spark Open: which one to choose
- Choose GPT-5.4 mini for cost-sensitive, high-volume workloads.
- Choose Muse Spark Open for long documents and large codebases (1.05M-token context).
- Choose Muse Spark Open if you want open weights you can self-host.