Model comparison
GPT-5.5 Pro vs Muse Spark 1.3
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 54.8 on the Noometry Index. Muse Spark 1.3 costs 34× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Last verified . 8 shared benchmarks.
MetaSummary
- They share 8 benchmarks with published results for both. GPT-5.5 Pro scores higher in 3 categories and Muse Spark 1.3 in 0 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in knowledge, where GPT-5.5 Pro leads 64.1 to 42.6.
- The biggest single-benchmark swing is FrontierMath Tier 4: 78% for GPT-5.5 Pro and 46.3% for Muse Spark 1.3.
- Muse Spark 1.3 is cheaper at $1.25 / $4.25 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
- GPT-5.5 Pro accepts more context: 1.05M tokens versus 1.05M.
Side by side
| GPT-5.5 Pro | Muse Spark 1.3 | |
|---|---|---|
| Provider | OpenAI | Meta |
| Noometry Index | 64.3 | 54.8 |
| Released | 2026-04-23 | 2026-09-02 |
| Weights | Proprietary | Proprietary |
| Context window | 1.05M | 1.05M |
| Max output | 128K | 131K |
| Input $ / M tokens | $30 | $1.25 |
| Output $ / M tokens | $180 | $4.25 |
| Results tracked | 14 | 37 |
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Category by category
Coding Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 56.6 (#21)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| CursorBench | — | 41.6% |
| LMArena WebDev | — | 1657 |
| SciCode | — | 59.7% |
| LMArena Coding | — | 1514 |
Agentic & Tool Use Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 38.6 (#30)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| APEX-Agents | — | 57.8% |
| GDP.pdf | — | 27.6% |
Reasoning GPT-5.5 Pro leads
GPT-5.5 Pro: 73.3 (#10), Muse Spark 1.3: 54.0 (#27)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| CritPt | 30.6% | 26% |
| Chess Puzzles | 64% | 38% |
| DTBench | 96% | 96.5% |
| LMCA | 53.9% | 53.9% |
| Epoch Capabilities Index | 162.07 | 156.75 |
| ARC-AGI-2 | 84.6% | — |
| SimpleBench | 76.9% | — |
| NYT Connections (extended) | — | 85.1% |
| ARC-AGI-1 | 96.5% | — |
| LMArena Hard Prompts | — | 1503 |
| Mystery Game Puzzles | — | 25% |
| Bench to the Future 3 | — | 0.14 |
Math GPT-5.5 Pro leads
GPT-5.5 Pro: 84.0 (#10), Muse Spark 1.3: 73.1 (#21)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | 74.4% |
| FrontierMath Tier 4 | 78% | 46.3% |
| OTIS Mock AIME 2024-2025 | 100% | 99.2% |
| ProofBench | — | 58% |
| LMArena Math | — | 1494 |
| FrontierMath (Feb 2025 set) | 52.4% | — |
| FrontierMath Tier 4 (v1) | 39.6% | — |
Knowledge GPT-5.5 Pro leads
GPT-5.5 Pro: 64.1 (#19), Muse Spark 1.3: 42.6 (#95)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| GPQA Diamond | 93.9% | — |
| LMArena Expert | — | 1516 |
Multimodal Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 43.7 (#22)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| LMArena Vision | — | 1309 |
| LMArena Document | — | 1471 |
Multilingual Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 57.4 (#8)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| LMArena Non-English | — | 1481 |
| LMArena Chinese | — | 1529 |
| LMArena French | — | 1524 |
| LMArena German | — | 1515 |
| LMArena Japanese | — | 1474 |
| LMArena Korean | — | 1501 |
| LMArena Russian | — | 1490 |
| LMArena Spanish | — | 1490 |
Instruction Following Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 77.5 (#22)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| LMArena Instruction Following | — | 1477 |
Long Context Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 45.6 (#32)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| LMArena Longer Query | — | 1488 |
Writing & Preference Not comparable
GPT-5.5 Pro: —, Muse Spark 1.3: 73.6 (#9)
| Benchmark | GPT-5.5 Pro | Muse Spark 1.3 |
|---|---|---|
| LMArena Text | — | 1490 |
| LMArena Creative Writing | — | 1455 |
| EQ-Bench Creative Writing | — | 1906 |
| LMArena Multi-Turn | — | 1482 |
Frequently asked questions
Is GPT-5.5 Pro better than Muse Spark 1.3?
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 54.8 on the Noometry Index. Muse Spark 1.3 costs 34× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.
Which is cheaper, GPT-5.5 Pro or Muse Spark 1.3?
Muse Spark 1.3 is cheaper. It lists at $1.25 per million input tokens and $4.25 per million output tokens; GPT-5.5 Pro lists at $30 and $180.
Which has the bigger context window?
GPT-5.5 Pro does, with 1.05M tokens against 1.05M.
How many benchmarks do GPT-5.5 Pro and Muse Spark 1.3 share?
8 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and Muse Spark 1.3 has 37.