Self-hosting and data control
Choose Muse Spark Open
Muse Spark Open has open weights, so you can run it on your own servers; GPT-6.1 Terra is only available through its provider.
Choose GPT-6.1 Terra for images as input and the latest release. Choose Muse Spark Open for self-hosting and data control.
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Choose Muse Spark Open
Muse Spark Open has open weights, so you can run it on your own servers; GPT-6.1 Terra is only available through its provider.
Choose GPT-6.1 Terra
GPT-6.1 Terra accepts images as input; Muse Spark Open does not.
Choose GPT-6.1 Terra
GPT-6.1 Terra is the newer release (Oct 26, 2026, against Oct 15, 2026 for Muse Spark Open).
| GPT-6.1 Terra | Muse Spark Open | |
|---|---|---|
| Provider | OpenAI | Meta |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $2.00 / 1M tokens | No data |
| Input | $1.00 / 1M tokens | No data |
| Output | $5.00 / 1M tokens | No data |
| Cached input | $0.05 / 1M tokens | No data |
| Context window | 1.05M | No data |
| Max output | 128k | No data |
| Released | Oct 26, 2026 | Oct 15, 2026 |
| Knowledge cutoff | No data | No data |
| Licence | Proprietary | Open weights |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching | Reasoning, Tool calling, Self-hostable |
| API model id | gpt-6.1-terra |
Leader in bold.
| Benchmark | GPT-6.1 Terra | Muse Spark Open |
|---|---|---|
| Intelligence Index | No data | 38.9 |
| SciCode | No data | 58.4% |
| GPQA Diamond | No data | 89% |
| Humanity's Last Exam | No data | 43.9% |
| MMMU-Pro (visual reasoning) | No data | 80.9% |
| Long-context reasoning (AA-LCR) | No data | 78.3% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Choose GPT-6.1 Terra for images as input and the latest release. Choose Muse Spark Open for self-hosting and data control.
A price comparison is not possible: one of them has no comparable published price.
GPT-6.1 Terra is made by OpenAI and Muse Spark Open by Meta. A price comparison is not possible: one of them has no comparable published price. Only GPT-6.1 Terra offers vision, structured output, prompt caching. Only Muse Spark Open offers self-hostable.
GPT-6.1 Terra was released on Oct 26, 2026 and Muse Spark Open on Oct 15, 2026.