GPT-5.5 Instant vs Muse Spark 1.3
GPT-5.5 Instant 
Muse Spark 1.3 Verdict
- Muse Spark 1.3 (xhigh) leads on quality: 63.9 vs 60.5.
- GPT-5.5 Instant is stronger in agents & tools, human preference, instruction following, maths, reasoning.
- Muse Spark 1.3 (xhigh) is stronger in coding, composite, knowledge, long context, multimodal.
- Muse Spark 1.3 (xhigh) is 5.6× cheaper ($2.00 vs $11.25 per 1M blended).
- Muse Spark 1.3 (xhigh) streams 1.5× faster (190 vs 129 tokens per second).
| Metric | GPT-5.5 Instant | Muse Spark 1.3 (xhigh) |
|---|---|---|
| BenchLeader Index | 60.5 | 63.9 |
| Agents & tools score | 70.7 | 60.2 |
| Coding score | 61.1 | 70.3 |
| Composite score | 62.9 | 78.6 |
| Human preference score | 67.5 | – |
| Instruction following score | 69.8 | – |
| Knowledge score | 69.4 | 75.1 |
| Long context score | 61.4 | 68.1 |
| Maths score | 42.5 | – |
| Multimodal score | 59.7 | 66.6 |
| Reasoning score | 62.6 | – |
| Blended price $/M | $11.25 | $2.00 |
| Output speed | 129 tok/s | 190 tok/s |
| Time to first answer | 16.8 s | 35.7 s |
| Context window | 400k | 1M |
| GPQA Diamond | 82.5% | – |
| FrontierMath Tiers 1–3 | 26.3% | – |
| FrontierMath Tier 4 | 2.4% | – |
| OTIS Mock AIME | 68.1% | – |
| SciCode | 48.6% | – |
| Epoch Capabilities Index | 142.5 | – |
| LMArena Text | 1474 | – |
| LMArena Hard Prompts | 1491 | – |
| LMArena Coding | 1514 | – |
| LMArena WebDev | – | 1625 |
| LMArena Vision | 1251 | – |
| LiveBench | – | 81.6% |
| LiveBench Reasoning | – | 89.7% |
| LiveBench Coding | – | 81.1% |
| LiveBench Agentic Coding | – | 64.1% |
| LiveBench Mathematics | – | 96.0% |
| LiveBench Data Analysis | – | 79.6% |
| LiveBench Language | – | 82.8% |
| AA Intelligence Index | 26.8 | 45.2 |
| IFBench | 71.5% | – |
| AA-LCR | 70.0% | 83.0% |
| MMMU-Pro | – | 82.0% |
| AA-Omniscience | 11.2 | 23.1 |
| Terminal-Bench Hard | 42.4% | – |
| GPQA Diamond (AA) | 84.7% | 94.1% |
| Humanity's Last Exam (AA) | 21.6% | 47.5% |
| SciCode (AA) | 52.5% | 59.7% |
| τ²-Bench Telecom (AA) | 49.4% | – |
| Terminal-Bench 2.1 (Vals) | – | 72.3% |
| Vals Index | – | 60.3 |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
GPT-5.5 Instant vs Muse Spark 1.3: questions
- Is GPT-5.5 Instant better than Muse Spark 1.3?
- Muse Spark 1.3 (xhigh) leads on quality: 63.9 vs 60.5. The BenchLeader Index combines every independent quality benchmark; Muse Spark 1.3 (xhigh) is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is GPT-5.5 Instant better than Muse Spark 1.3 for coding?
- Muse Spark 1.3 scores higher in coding (70 vs 61 on the category index, where 50 is average).
- Is GPT-5.5 Instant better than Muse Spark 1.3 for agentic tasks?
- GPT-5.5 Instant scores higher in agentic tasks (71 vs 60 on the category index, where 50 is average).
- Which is cheaper, GPT-5.5 Instant or Muse Spark 1.3?
- Muse Spark 1.3 is cheaper: $2.00 against $11.25 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-5.5 Instant or Muse Spark 1.3?
- Muse Spark 1.3 streams faster: 190 against 129 output tokens per second.
- Which has the larger context window?
- Muse Spark 1.3 accepts more context: 1M against 400k tokens.