GPT-5.5 Instant vs Muse Spark
GPT-5.5 Instant 
Muse Spark Verdict
- Muse Spark leads on quality: 65.6 vs 60.5.
- GPT-5.5 Instant is stronger in agents & tools, knowledge.
- Muse Spark is stronger in coding, composite, human preference, instruction following, long context, maths, multimodal, reasoning.
| Metric | GPT-5.5 Instant | Muse Spark |
|---|---|---|
| BenchLeader Index | 60.5 | 65.6 |
| Agents & tools score | 70.7 | 66.4 |
| Coding score | 61.1 | 66.2 |
| Composite score | 62.9 | 68.6 |
| Human preference score | 67.5 | 69.3 |
| Instruction following score | 69.8 | 79.7 |
| Knowledge score | 69.4 | 64.6 |
| Long context score | 61.4 | 65.5 |
| Maths score | 42.5 | 56.4 |
| Multimodal score | 59.7 | 65.9 |
| Reasoning score | 62.6 | 70.2 |
| Blended price $/M | $11.25 | – |
| Output speed | 129 tok/s | – |
| Time to first answer | 16.8 s | – |
| Context window | 400k | 262k |
| GPQA Diamond | 82.5% | 89.8% |
| FrontierMath Tiers 1–3 | 26.3% | – |
| FrontierMath Tier 4 | 2.4% | – |
| OTIS Mock AIME | 68.1% | 88.9% |
| Humanity's Last Exam | – | 40.6% |
| SciCode | 48.6% | 51.5% |
| ProofBench | – | 17.0% |
| Epoch Capabilities Index | 142.5 | 152.1 |
| LMArena Text | 1474 | 1488 |
| LMArena Hard Prompts | 1491 | 1505 |
| LMArena Coding | 1514 | 1526 |
| LMArena Vision | 1251 | 1306 |
| AA Intelligence Index | 26.8 | 31.3 |
| IFBench | 71.5% | 75.9% |
| AA-LCR | 70.0% | 78.0% |
| MMMU-Pro | – | 80.5% |
| AA-Omniscience | 11.2 | 7.2 |
| Terminal-Bench Hard | 42.4% | 45.5% |
| GPQA Diamond (AA) | 84.7% | 88.4% |
| Humanity's Last Exam (AA) | 21.6% | 40.7% |
| SciCode (AA) | 52.5% | – |
| τ²-Bench Telecom (AA) | 49.4% | 91.5% |
| AIME (Vals) | – | 96.9% |
| MMLU-Pro | – | 87.3% |
| LegalBench | – | 84.2% |
| CorpFin | – | 65.1% |
| TaxEval | – | 77.7% |
| SWE-bench (Vals) | – | 74.4% |
| GPQA Diamond (Vals) | – | 89.7% |
| SWE-Bench Pro | – | 55.0% |
| MCP Atlas | – | 82.2% |
| MultiChallenge | – | 75.5% |
| PRBench Finance | – | 52.4% |
| PRBench Legal | – | 52.3% |
| MultiNRC | – | 59.0% |
| TutorBench | – | 68.5% |
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: questions
- Is GPT-5.5 Instant better than Muse Spark?
- Muse Spark leads on quality: 65.6 vs 60.5. The BenchLeader Index combines every independent quality benchmark; Muse Spark 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 for coding?
- Muse Spark scores higher in coding (66 vs 61 on the category index, where 50 is average).
- Is GPT-5.5 Instant better than Muse Spark for agentic tasks?
- GPT-5.5 Instant scores higher in agentic tasks (71 vs 66 on the category index, where 50 is average).
- Which has the larger context window?
- GPT-5.5 Instant accepts more context: 400k against 262k tokens.