Hardest reasoning tasks
Choose GPT-5.6 Terra
GPT-5.6 Terra scores 42.1 on the Artificial Analysis Intelligence Index, against 33.7 for Muse Spark 1.1.
GPT-5.6 Terra vs Muse Spark 1.1: price, context and capabilities
Choose GPT-5.6 Terra for the hardest reasoning tasks and reasoning over long documents; on the other points the two are level or the data is missing.
In short
- A price comparison is not possible: one of them has no comparable published price.
- GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
- Only GPT-5.6 Terra offers reasoning, structured output, prompt caching, batch api.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Reasoning over long documents
Choose GPT-5.6 Terra
GPT-5.6 Terra scores 83% on Long-context reasoning (AA-LCR), against 77.7% for Muse Spark 1.1.
Specifications side by side
| GPT-5.6 Terra | Muse Spark 1.1 | |
|---|---|---|
| Provider | OpenAI | Meta |
| Category | Language models | Language models |
| Status | Generally available | Legacy |
| Headline price | $4.50 / 1M tokens | No data |
| Input | $2.00 / 1M tokens | No data |
| Output | $12.00 / 1M tokens | No data |
| Cached input | $0.20 / 1M tokens | No data |
| Context window | 1.05M | 1.05M |
| Max output | 128k | No data |
| Released | Jul 9, 2026 | Jul 9, 2026 |
| Knowledge cutoff | February 2026 | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Tool calling |
| API model id | gpt-5.6-terra | muse-spark-1.1 |
Benchmarks side by side
Leader in bold.
| Benchmark | GPT-5.6 Terra | Muse Spark 1.1 |
|---|---|---|
| Intelligence Index | 42.1 | 33.7 |
| SciCode | 55% | 58.8% |
| GPQA Diamond | 92.5% | 89.8% |
| Humanity's Last Exam | 42.9% | 46.2% |
| Long-context reasoning (AA-LCR) | 83% | 77.7% |
| Terminal-Bench Hard | 57.6% | No data |
| IFBench (instruction following) | 71.2% | No data |
| τ²-Bench (agentic tool use) | 86.3% | No data |
| MMMU-Pro (visual reasoning) | 80.7% | No data |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose GPT-5.6 Terra or Muse Spark 1.1?
Choose GPT-5.6 Terra for the hardest reasoning tasks and reasoning over long documents; on the other points the two are level or the data is missing.
Which is cheaper, GPT-5.6 Terra or Muse Spark 1.1?
A price comparison is not possible: one of them has no comparable published price.
Which has the larger context window, GPT-5.6 Terra or Muse Spark 1.1?
GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
What is the difference between GPT-5.6 Terra and Muse Spark 1.1?
GPT-5.6 Terra is made by OpenAI and Muse Spark 1.1 by Meta. A price comparison is not possible: one of them has no comparable published price. GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M. Only GPT-5.6 Terra offers reasoning, structured output, prompt caching, batch api.