GPT-5.5 Instant vs Muse Spark 1.2
GPT-5.5 Instant 
Muse Spark 1.2 Verdict
- Muse Spark 1.2 leads on quality: 62.7 vs 60.5.
- GPT-5.5 Instant is stronger in agents & tools, human preference, instruction following, multimodal.
- Muse Spark 1.2 is stronger in coding, composite, knowledge, long context, maths, reasoning.
- Muse Spark 1.2 is 5.6× cheaper ($2.00 vs $11.25 per 1M blended).
- Muse Spark 1.2 streams 1.5× faster (193 vs 129 tokens per second).
| Metric | GPT-5.5 Instant | Muse Spark 1.2 |
|---|---|---|
| BenchLeader Index | 60.5 | 62.7 |
| Agents & tools score | 70.7 | – |
| Coding score | 61.1 | 66.5 |
| Composite score | 62.9 | 79.3 |
| Human preference score | 67.5 | – |
| Instruction following score | 69.8 | – |
| Knowledge score | 69.4 | 77.1 |
| Long context score | 61.4 | 66.0 |
| Maths score | 42.5 | 54.3 |
| Multimodal score | 59.7 | – |
| Reasoning score | 62.6 | 70.7 |
| Blended price $/M | $11.25 | $2.00 |
| Output speed | 129 tok/s | 193 tok/s |
| Time to first answer | 16.8 s | 23.4 s |
| Context window | 400k | 1.0M |
| GPQA Diamond | 82.5% | – |
| FrontierMath Tiers 1–3 | 26.3% | – |
| FrontierMath Tier 4 | 2.4% | – |
| OTIS Mock AIME | 68.1% | – |
| SimpleBench | – | 74.5% |
| SciCode | 48.6% | – |
| ProofBench | – | 43.0% |
| Epoch Capabilities Index | 142.5 | 155.5 |
| LMArena Text | 1474 | – |
| LMArena Hard Prompts | 1491 | – |
| LMArena Coding | 1514 | – |
| LMArena Vision | 1251 | – |
| AA Intelligence Index | 26.8 | 39.8 |
| IFBench | 71.5% | – |
| AA-LCR | 70.0% | 79.0% |
| AA-Omniscience | 11.2 | 27.2 |
| Terminal-Bench Hard | 42.4% | – |
| GPQA Diamond (AA) | 84.7% | 90.4% |
| Humanity's Last Exam (AA) | 21.6% | 45.5% |
| SciCode (AA) | 52.5% | 57.4% |
| τ²-Bench Telecom (AA) | 49.4% | – |
| IOI | – | 49.5% |
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 1.2: questions
- Is GPT-5.5 Instant better than Muse Spark 1.2?
- Muse Spark 1.2 leads on quality: 62.7 vs 60.5. The BenchLeader Index combines every independent quality benchmark; Muse Spark 1.2 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 1.2 for coding?
- Muse Spark 1.2 scores higher in coding (67 vs 61 on the category index, where 50 is average).
- Which is cheaper, GPT-5.5 Instant or Muse Spark 1.2?
- Muse Spark 1.2 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 1.2?
- Muse Spark 1.2 streams faster: 193 against 129 output tokens per second.
- Which has the larger context window?
- Muse Spark 1.2 accepts more context: 1.0M against 400k tokens.