GPT-5.5 vs Muse Spark
Full profiles: GPT-5.5 (OpenAI) and Muse Spark (Meta): every benchmark, price and rank.
Updated · Data from 11 sources
As of 25 Oct 2026, GPT-5.5 (xhigh) and Muse Spark are neck and neck on quality (66.1 vs 64.3, inside the ±4.8 margin of error) and close on price, so pick on the category that matters to you. Pick GPT-5.5 for maths (70 vs 59); pick Muse Spark for coding (65 vs 61).
GPT-5.5 benchmarks 
Muse Spark benchmarks Which to pick for…
The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.
| Use case | Pick | Why | Confidence |
|---|---|---|---|
| Coding | Muse Spark | 65 vs 61 category score; SciCode 51.5% vs 55.8% | Medium |
| Agents & tool use | Muse Spark | 66 vs 62 category score; MCP Atlas 82.2% vs 75.3% | Medium |
| Maths | GPT-5.5 | 70 vs 59 category score; ProofBench 50.0% vs 17.0% | High |
| Reasoning | GPT-5.5 | 76 vs 65 category score; CritPt 27.1% vs 11.3% | High |
| Knowledge | GPT-5.5 | 65 vs 63 category score; AA-Omniscience 20.5 vs 7.2 | Medium |
| Long documents | GPT-5.5 | 67 vs 64 category score; AA-LCR 84.3% vs 78.0% | Medium |
| Images and other media | Muse Spark | 65 vs 63 category score; MMMU-Pro 80.5% vs 79.9% | Medium |
| Following instructions | Muse Spark | 77 vs 74 category score; IFBench 75.9% vs 75.8% | Medium |
| Chat quality (human preference) | – | Only Muse Spark has an Arena rating (68 category score) | Not comparable |
| High volume on a budget | Neither flagship | A smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs | – |
Key differences
- GPT-5.5 (xhigh) and Muse Spark are neck and neck on quality (66.1 vs 64.3, within the ±4.8 margin).
- GPT-5.5 (xhigh) is stronger in composite, knowledge, long context, maths, reasoning.
- Muse Spark is stronger in agents & tools, coding, instruction following, multimodal, human preference.
At a glance
| Spec | GPT-5.5 | Muse Spark |
|---|---|---|
| Developer | OpenAI | Meta |
| Released | 23 Apr 2026 | 8 Apr 2026 |
| Context window (tokens) | 1,050,000 | 262,144 |
| Compared at | GPT-5.5 (xhigh) | Muse Spark |
| Open weights | No | No |
| Price in / out / cached input per 1M | $5.00 / $30.00 / $0.500 | – |
Category by category
Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.
| Category | GPT-5.5 (xhigh) | Muse Spark | Leader |
|---|---|---|---|
| Reasoning | 75.5 | 65.3 | GPT-5.5 |
| Coding | 61.1 | 65.0 | Muse Spark |
| Agents & tools | 62.3 | 66.1 | Muse Spark |
| Maths | 69.7 | 59.1 | GPT-5.5 |
| Knowledge | 65.3 | 63.3 | GPT-5.5 |
| Instruction following | 73.9 | 77.3 | Muse Spark |
| Human preference | – | 68.3 | not comparable |
| Multimodal | 62.9 | 64.5 | Muse Spark |
| Long context | 67.3 | 64.0 | GPT-5.5 |
| Composite | 72.4 | 64.5 | GPT-5.5 |
Where sources disagree
Across the 29 benchmarks both have, GPT-5.5 leads 22, Muse Spark leads 7. Independent sources split: GPT-5.5 leads on AA Intelligence Index v4.3.2; Muse Spark leads on Arena Text.
| Overall index | GPT-5.5 (xhigh) | Muse Spark | Leader |
|---|---|---|---|
| BenchLeader Index | 66.1 | 64.3 | neck and neck |
| AA Intelligence Index v4.3.2 | 38.4 | 31.3 | GPT-5.5 |
| Arena Text | 1482† | 1489 | Muse Spark |
Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).
Price, speed and latency
List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.
| Measure | GPT-5.5 (xhigh) | Muse Spark |
|---|---|---|
| Blended price per 1M tokens | $11.25 | – |
| Input / output per 1M | $5.00 / $30.00 | – / – |
| Cached input per 1M | $0.500 | – |
| Price per task: chat reply | $0.011 | – |
| Price per task: summarize a 30-page report | $0.078 | – |
| Price per task: code edit | $0.075 | – |
| Price per task: agentic coding session | $0.420 | – |
| Price per task: structured extraction | $0.016 | – |
| Cost to run a full benchmark suite | $2.63 | – |
| Output speed | 86 tok/s | – |
| Time to first answer | 39.1 s | – |
| Time to a complete answer | 45.0 s | – |
Each model is compared at its best-ranked reasoning-effort setting. GPT-5.5 (xhigh) scores 66.1 and takes 39 s to its first answer token; GPT-5.5 (high) scores 65.3 in 14 s, GPT-5.5 (medium) scores 62.9 in 3 s. Muse Spark scores 64.3. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.
Every benchmark
142 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.
| Metric | Publisher | GPT-5.5 (xhigh) | Muse Spark |
|---|---|---|---|
| BenchLeader Index | BenchLeader | 66.1 | 64.3 |
| Agents & tools score | BenchLeader | 62.3 | 66.1 |
| Coding score | BenchLeader | 61.1 | 65.0 |
| Composite score | BenchLeader | 72.4 | 64.5 |
| Instruction following score | BenchLeader | 73.9 | 77.3 |
| Knowledge score | BenchLeader | 65.3 | 63.3 |
| Long context score | BenchLeader | 67.3 | 64.0 |
| Maths score | BenchLeader | 69.7 | 59.1 |
| Multimodal score | BenchLeader | 62.9 | 64.5 |
| Reasoning score | BenchLeader | 75.5 | 65.3 |
| Human preference score | BenchLeader | – | 68.3 |
| Blended price $/M | BenchLeader | $11.25 | – |
| Output speed | BenchLeader | 86 tok/s | – |
| Time to first answer | BenchLeader | 39.1 s | – |
| Context window | BenchLeader | 1,050,000 tokens | 262,144 tokens |
| Reasoning | |||
| GPQA Diamond | Epoch AI Benchmarking Hub | 90.7%† | 89.8% |
| Humanity's Last Exam | Scale AI / CAIS | – | 40.6% |
| SimpleBench | SimpleBench | 69.0%† | – |
| Arena Hard Prompts | Arena (LMArena) | 1499† | 1506 |
| LiveBench 2.0 Reasoning | LiveBench | 89.7%† | – |
| LiveBench 1.0 Reasoning | LiveBench | 89.7% | – |
| GPQA Diamond (AA) | Artificial Analysis | 93.5% | 88.4% |
| Humanity's Last Exam (AA) | Artificial Analysis | 45.8% | 40.7% |
| GPQA Diamond (Vals) | Vals AI | 93.2% | 89.7% |
| Kagi LLM Benchmark | Kagi LLM Benchmark | 88.8%† | – |
| ARC-AGI-1 | ARC Prize | 95.0% | – |
| ARC-AGI-2 | ARC Prize | 85.0% | – |
| ARC-AGI-3 | ARC Prize | 0.4%† | – |
| CritPt | Artificial Analysis | 27.1% | 11.3% |
| Chess Puzzles | Epoch AI Benchmarking Hub | 63.0% | – |
| Mystery Game Puzzles | Epoch AI Benchmarking Hub | 56.0% | – |
| CL-bench Life | Epoch AI Benchmarking Hub | 22.2%† | – |
| LMCA | Epoch AI Benchmarking Hub | 54.3% | – |
| DTBench | Epoch AI Benchmarking Hub | 96.0% | – |
| ForecastBench | ForecastBench | 64.4%† | – |
| BTF-3 | Epoch AI Benchmarking Hub | 14.3%† | – |
| Coding | |||
| SciCode | SciCode | 55.8% | 51.5% |
| WeirdML | WeirdML | 84.9% | – |
| FrontierCode | Cognition | 43.0%† | – |
| GSO-Bench | GSO-Bench | 40.2% | – |
Show all 142 benchmarks
| Metric | Publisher | GPT-5.5 (xhigh) | Muse Spark |
|---|---|---|---|
| Coding | |||
| Arena Coding | Arena (LMArena) | 1511† | 1529 |
| Arena WebDev | Arena (LMArena) | 1513 | – |
| LiveBench 2.0 Coding | LiveBench | 85.1%† | – |
| LiveBench 1.0 Coding | LiveBench | 82.2% | – |
| SciCode (AA) | Artificial Analysis | 55.8% | – |
| LiveCodeBench | Vals AI | 85.3% | – |
| SWE-bench (Vals) | Vals AI | 82.6% | 74.4% |
| SWE-Bench Pro | Scale AI SEAL | – | 55.0% |
| Code Migration | Vals AI | 45.2% | – |
| ProgramBench | Vals AI | 0.5% | – |
| Vibe Code Bench v1.1 | Vals AI | 69.8% | 19.7% |
| SWE-Bench Pro (private) | Scale AI SEAL | – | 55.0% |
| SWE Atlas: Codebase QnA | Scale AI SEAL | 45.4% | 24.2% |
| SWE Atlas: Refactoring | Scale AI SEAL | 44.8% | – |
| SWE Atlas: Test Writing | Scale AI SEAL | 42.6% | 31.1% |
| MirrorCode | Epoch AI Benchmarking Hub | 10.0%† | – |
| Surface Evolver Bench | Epoch AI Benchmarking Hub | 88.1%† | – |
| DeepSWE v1.1 | Epoch AI Benchmarking Hub | 67.0% | – |
| ALE-Bench | Epoch AI Benchmarking Hub | 1943.0 | – |
| Terminal-Bench 4.0 (AA) | Artificial Analysis | 14.7% | – |
| Terminal-Bench 2.1 (AA) | Artificial Analysis | 84.3% | 62.2% |
| Agents & tools | |||
| Terminal-Bench | Terminal-Bench | 84.7%† | – |
| OSWorld-Verified 2.0 | OSWorld | 13.0% | – |
| Remote Labor Index | Scale AI / CAIS | 6.3%† | – |
| APEX-Agents | Mercor | 55.1%† | – |
| LiveBench Long Agentic | LiveBench | 44.6%† | – |
| LiveBench Browser | LiveBench | 48.0%† | – |
| LiveBench Agentic Coding | LiveBench | 54.0% | – |
| Terminal-Bench Hard | Artificial Analysis | 60.6% | 45.5% |
| τ²-Bench Telecom (AA) | Artificial Analysis | 93.9% | 91.5% |
| Terminal-Bench 2.1 (Vals) | Vals AI | 76.4%† | – |
| MCP Atlas | Scale AI SEAL | 75.3% | 82.2% |
| HiL-Bench | Scale AI SEAL | 39.7%† | – |
| τ³-bench Banking | τ²-bench | 44.6% | – |
| τ³-Banking (AA) | Artificial Analysis | 39.0% | – |
| ITBench SRE (AA) | Artificial Analysis | 45.8% | – |
| Analyst Agent (AA) | Artificial Analysis | 50.0% | – |
| APEX-Agents (AA) | Artificial Analysis | 37.7% | – |
| Finance Agent v2 | Vals AI | 51.8% | – |
| Harvey's Legal Agent Benchmark v1 | Vals AI | 3.8% | – |
| Legal Research Bench | Vals AI | 40.4% | – |
| SkillsBench | Vals AI | 62.2% | – |
| SREBench | Vals AI | 3.8% | – |
| Tax Agent Bench | Vals AI | 21.8% | – |
| Terminal-Bench 2.0 (Vals) | Vals AI | 73.2%† | 59.5% |
| Time Horizon Index: KSP | Vals AI | 8.3% | – |
| DeepResearch Bench | DeepResearch Bench | 54.0%† | – |
| PostTrainBench | Epoch AI Benchmarking Hub | 27.2% | – |
| ExploitBench | Epoch AI Benchmarking Hub | 47.4%† | – |
| GBAEval | Epoch AI Benchmarking Hub | 53.2%† | – |
| Vending-Bench 2 | Andon Labs | 7523.8† | – |
| AutomationBench | Artificial Analysis | 47.3% | – |
| GDP.pdf (AA) | Artificial Analysis | 21.2% | – |
| EnterpriseOps-Gym | Artificial Analysis | 46.6% | – |
| AA-Briefcase v1.1 | Artificial Analysis | 1136 | – |
| Maths | |||
| FrontierMath Tiers 1–3 | Epoch AI Benchmarking Hub | 85.3% | – |
| FrontierMath Tier 4 | Epoch AI Benchmarking Hub | 72.5% | – |
| OTIS Mock AIME | Epoch AI Benchmarking Hub | 84.4%† | 88.9% |
| ProofBench | Vals AI | 50.0% | 17.0% |
| LiveBench Mathematics | LiveBench | 95.9% | – |
| AIME (Vals) | Vals AI | – | 96.9% |
| AIME 2026 | MathArena | 100.0% | – |
| HMMT February 2026 | MathArena | 98.5% | – |
| USAMO 2026 | MathArena | 98.2% | – |
| MathArena Apex | MathArena | 80.2% | – |
| Arena Maths | Arena (LMArena) | 1501† | 1467 |
| Knowledge | |||
| SimpleQA Verified | Epoch AI Benchmarking Hub | 63.0% | – |
| LiveBench 2.0 Data Analysis | LiveBench | 81.6%† | – |
| LiveBench Research | LiveBench | 61.6%† | – |
| LiveBench 1.0 Data Analysis | LiveBench | 81.6% | – |
| AA-Omniscience | Artificial Analysis | 20.5 | 7.2 |
| MMLU-Pro | Vals AI | 88.1% | 87.3% |
| LegalBench | Vals AI | 86.5% | 84.2% |
| CorpFin | Vals AI | 68.4% | 65.1% |
| TaxEval | Vals AI | 75.0% | 77.7% |
| PRBench Finance | Scale AI SEAL | – | 52.4% |
| PRBench Legal | Scale AI SEAL | – | 52.3% |
| MultiNRC | Scale AI SEAL | – | 59.0% |
| CaseLaw v2 | Vals AI | 66.2% | 63.1% |
| Excel Modeling Benchmark | Vals AI | 64.5% | – |
| MedCode | Vals AI | 49.1% | 51.3% |
| MedScribe | Vals AI | 86.9% | 85.9% |
| Public Benefits Bench v1.1 | Vals AI | 60.9% | – |
| DrugDiscoveryBench | Scale AI SEAL | 51.6% | – |
| EBR-bench | Epoch AI Benchmarking Hub | 34.3% | – |
| GDP.pdf | Epoch AI Benchmarking Hub | 26.0% | – |
| AA-Omniscience: accuracy | Artificial Analysis | 58.0% | 49.6% |
| AA-Omniscience: non-hallucination | Artificial Analysis | 11.0% | 15.8% |
| Instruction following | |||
| LiveBench Language | LiveBench | 87.4% | – |
| LiveBench Instruction Following | LiveBench | 70.7% | – |
| IFBench | Artificial Analysis | 75.8% | 75.9% |
| MultiChallenge | Scale AI SEAL | – | 75.5% |
| TutorBench | Scale AI SEAL | – | 68.5% |
| Arena Instruction Following | Arena (LMArena) | 1475† | 1465 |
| Human preference | |||
| Arena Text | Arena (LMArena) | 1477† | 1489 |
| EQ-Bench 4 | EQ-Bench | 1294† | – |
| Arena Creative Writing | Arena (LMArena) | 1448† | 1464 |
| Arena Multi-turn | Arena (LMArena) | 1484† | 1494 |
| Arena Longer Queries | Arena (LMArena) | 1487† | 1476 |
| Multimodal | |||
| Arena Vision | Arena (LMArena) | 1297† | 1306 |
| LiveBench Design | LiveBench | 70.3%† | – |
| MMMU-Pro | Artificial Analysis | 79.9% | 80.5% |
| MMMU-Pro (official) | MMMU | – | 80.4%† |
| MMMU-Pro (Vals) | Vals AI | 88.3% | 87.4% |
| MortgageTax | Vals AI | 68.8% | – |
| SAGE | Vals AI | 51.5% | – |
| Blueprint-Bench 2 | Epoch AI Benchmarking Hub | 36.2%† | – |
| Long context | |||
| AA-LCR | Artificial Analysis | 84.3% | 78.0% |
| Arena Document | Arena (LMArena) | 1483† | 1467 |
| MLCR | Artificial Analysis | 28.9% | – |
| Composite | |||
| Epoch Capabilities Index | Epoch AI Benchmarking Hub | 159.7† | 152.0 |
| LiveBench 2.0 | LiveBench | 68.7%† | – |
| LiveBench 1.0 | LiveBench | 80.2% | – |
| AA Intelligence Index v4.3.2 | Artificial Analysis | 38.4 | 31.3 |
| Vals RSI Index | Vals AI | 16.5% | – |
| Vals Multimodal Index | Vals AI | 68.1% | – |
| Safety & honesty | |||
| FORTRESS | Scale AI SEAL | 16.3% | 20.2% |
Data as of 2026-10-25. Best configuration of each model; every score links to its source on the model pages.
What changed
- GPT-5.5 (xhigh): 1 new result (AA-Briefcase v1.1).
- GPT-5.5 (xhigh): 2 new results (Harvey's Legal Agent Benchmark v1, Vals RSI Index).
- GPT-5.5 (xhigh): 1 score revision.
- GPT-5.5 (xhigh): 6 new results (USAMO 2026, AutomationBench, GDP.pdf (AA)…).
- GPT-5.5 (xhigh): BenchLeader Index 66.2 → 65.7.
- GPT-5.5 (xhigh): 1 score revision.
- GPT-5.5 (xhigh): 1 new result (Chess Puzzles); 1 score revision.
- Muse Spark: 1 new result (PRBench Legal).
- GPT-5.5 (xhigh): 1 new result (SWE Atlas: Codebase QnA).
- Muse Spark: 1 new result (SWE Atlas: Codebase QnA).
Related comparisons
- GPT-5.5 vs Claude Opus 5.5
- GPT-5.5 vs Gemini 4 Argon
- GPT-5.5 vs Muse Wonder Full
- Muse Spark vs Claude Opus 5.5
- Muse Spark vs Gemini 4 Argon
- Muse Spark vs Muse Wonder Full
- Muse Spark vs Claude Fable 5.1
- GPT-5.4 vs Muse Spark
Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs
GPT-5.5 vs Muse Spark: questions
- Is GPT-5.5 better than Muse Spark?
- GPT-5.5 (xhigh) and Muse Spark are neck and neck on quality (66.1 vs 64.3, within the ±4.8 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 2026-10-25, so check the category scores for your use.
- Is GPT-5.5 better than Muse Spark for coding?
- Muse Spark scores higher in coding (65 vs 61 on the category index, where 50 is average). On SciCode, the top shared coding benchmark, it is 55.8% for GPT-5.5 against 51.5% for Muse Spark.
- Is GPT-5.5 better than Muse Spark for agents and tool use?
- Muse Spark scores higher in agentic tasks (66 vs 62 on the category index, where 50 is average). On MCP Atlas, the top shared agents & tools benchmark, it is 75.3% for GPT-5.5 against 82.2% for Muse Spark.
- Which is better for long documents?
- GPT-5.5 scores higher on long-context benchmarks (67 vs 64). GPT-5.5 accepts more context: 1,050,000 against 262,144 tokens for Muse Spark.
- Do independent benchmarks agree on GPT-5.5 vs Muse Spark?
- Across the 29 benchmarks both have, GPT-5.5 leads 22, Muse Spark leads 7. Independent sources split: GPT-5.5 leads on AA Intelligence Index v4.3.2; Muse Spark leads on Arena Text.
- When was GPT-5.5 released?
- GPT-5.5 was released on 23 Apr 2026.