Claude Opus 5.5 vs Muse Spark Open
As of 18 Oct 2026, Claude Opus 5.5 (max) leads on quality (71.6 vs 61.2 on the BenchLeader Index), but Muse Spark Open (xhigh) costs 4.0× less, so it is the better buy unless you need the extra quality.
Claude Opus 5.5 
Muse Spark Open Key differences
- Claude Opus 5.5 (max) leads on quality: 71.6 vs 61.2.
- Claude Opus 5.5 (max) is stronger in agents & tools, coding, composite, knowledge, long context, maths, multimodal, reasoning.
- Muse Spark Open (xhigh) is 4.0× cheaper ($2.00 vs $8.00 per 1M blended).
- Muse Spark Open (xhigh) streams 1.4× faster (140 vs 97 tokens per second).
Choose Claude Opus 5.5 (max) if
- reasoning is the priority (76 vs 66 on the category score)
- multimodal is the priority (71 vs 64 on the category score)
- knowledge is the priority (79 vs 73 on the category score)
Choose Muse Spark Open (xhigh) if
- cost matters: $2.00 against $8.00 per million tokens blended
- you need fast output: 140 against 97 tokens per second
- the wait for the first word matters: 15.0 s against 556.9 s to first answer
- you want to run it yourself: its weights are open
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 | Claude Opus 5.5 (max) | Muse Spark Open (xhigh) | Leader |
|---|---|---|---|
| Reasoning | 75.6 | 65.5 | Claude Opus 5.5 |
| Coding | 82.4 | – | not comparable |
| Agents & tools | 63.0 | – | not comparable |
| Maths | 74.3 | – | not comparable |
| Knowledge | 78.7 | 72.5 | Claude Opus 5.5 |
| Multimodal | 71.0 | 64.1 | Claude Opus 5.5 |
| Long context | 67.5 | 64.2 | Claude Opus 5.5 |
| Composite | 84.2 | 73.1 | Claude Opus 5.5 |
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 | Claude Opus 5.5 (max) | Muse Spark Open (xhigh) |
|---|---|---|
| Blended price per 1M tokens | $8.00 | $2.00 |
| Input / output per 1M | $4.00 / $20.00 | $1.25 / $4.25 |
| Price per task: chat reply | $0.0076 | $0.0018 |
| Price per task: summarise a 30-page report | $0.060 | $0.018 |
| Price per task: code edit | $0.054 | $0.014 |
| Price per task: agentic coding session | $0.320 | $0.092 |
| Price per task: structured extraction | $0.012 | $0.0034 |
| Cost to run a full benchmark suite | $5.98 | $0.844 |
| Output speed | 97 tok/s | 140 tok/s |
| Time to first answer | 556.9 s | 15.0 s |
| Time to a complete answer | 562.1 s | 18.6 s |
Every benchmark
| Metric | Claude Opus 5.5 (max) | Muse Spark Open (xhigh) |
|---|---|---|
| BenchLeader Index | 71.6 | 61.2 |
| Agents & tools score | 63.0 | – |
| Coding score | 82.4 | – |
| Composite score | 84.2 | 73.1 |
| Knowledge score | 78.7 | 72.5 |
| Long context score | 67.5 | 64.2 |
| Maths score | 74.3 | – |
| Multimodal score | 71.0 | 64.1 |
| Reasoning score | 75.6 | 65.5 |
| Blended price $/M | $8.00 | $2.00 |
| Output speed | 97 tok/s | 140 tok/s |
| Time to first answer | 556.9 s | 15.0 s |
| Context window | 1M | 1.0M |
| GPQA Diamond | 90.6% | – |
| FrontierMath Tiers 1–3 | 91.2% | – |
| FrontierMath Tier 4 | 95.0% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 72.2% | – |
| Terminal-Bench | 64.8% | – |
| SciCode | 66.9% | – |
| APEX-Agents | 73.5% | – |
| ProofBench | 100.0% | – |
| Arena WebDev | 1807 | – |
| Arena Agent | 18.9 | – |
| LiveBench | 83.2% | – |
| LiveBench Reasoning | 92.2% | – |
| LiveBench Coding | 89.3% | – |
| LiveBench Agentic Coding | 71.7% | – |
| LiveBench Mathematics | 97.1% | – |
| LiveBench Data Analysis | 80.3% | – |
| LiveBench Language | 86.3% | – |
| LiveBench Instruction Following | 65.7% | – |
| AA Intelligence Index v4.3.2 | 57.6 | 38.9 |
| AA-LCR | 84.7% | 78.3% |
| MMMU-Pro | 87.7% | 80.9% |
| AA-Omniscience | 46.4 | 24.6 |
| GPQA Diamond (AA) | – | 89.0% |
| Humanity's Last Exam (AA) | 61.4% | 43.9% |
| SciCode (AA) | 66.9% | 58.5% |
| Vals Index | – | 46.6 |
| ARC-AGI-1 | 97.5% | – |
| ARC-AGI-2 | 91.7% | – |
| CritPt | 31.7% | 14.9% |
| GDPval-AA v2.1 | 68.3% | 45.1% |
| ITBench SRE (AA) | 38.2% | – |
| Analyst Agent (AA) | 56.3% | – |
| Code Migration | – | 21.2% |
| CUA-bench | 14.0% | – |
| Excel Modeling Benchmark | – | 53.7% |
| Finance Agent v2 | – | 61.3% |
| Harvey's Legal Agent Benchmark | – | 16.7% |
| Legal Research Bench | – | 38.5% |
| Tax Agent Bench | – | 26.3% |
| Terminal-Bench 4.0 (Vals) | – | 6.6% |
| Vibe Code Bench v1.1 | – | 76.2% |
| Chess Puzzles | 67.0% | – |
| EBR-bench | 71.4% | – |
| Mystery Game Puzzles | 71.0% | – |
| MirrorCode | 77.4% | – |
| LMCA | 68.2% | – |
| DTBench | 98.9% | – |
| CursorBench | 57.8% | – |
| GDP.pdf | 30.6% | – |
| FrontierSWE | 62.3% | – |
| Terminal-Bench 4.0 (AA) | 59.6% | 8.1% |
| Terminal-Bench 2.1 (AA) | – | 76.4% |
| AutomationBench | 69.5% | 49.7% |
| GDP.pdf | 26.2% | 18.6% |
| MLCR | 66.7% | – |
| Harvey LAB-AA v1.1 | 4.2% | – |
| AA-Omniscience: accuracy | 66.2% | 39.3% |
| AA-Omniscience: non-hallucination | 41.4% | 75.9% |
| AA-Briefcase v1.1 | 1803 | 1279 |
| FrontierCode 1.1 (AA) | 52.2% | – |
| Terminal-Bench-Science 0.1 (AA) | 59.0% | – |
| AA Cyber Index | 2866.4% | – |
| CWE-Bench (AA) | 58.3% | – |
| DeepSec-Bench (AA) | 26.9% | – |
| CyberGym end-to-end (AA) | 0.8% | – |
| AA-3D | 1191 | – |
| AA Openness Index | – | 27.8 |
Data as of 2026-10-18. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 5.5 vs Muse Spark Open: questions
- Is Claude Opus 5.5 better than Muse Spark Open?
- Claude Opus 5.5 (max) leads on quality: 71.6 vs 61.2. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5.5 (max) is ahead overall as of 2026-10-18, but check the category scores for your use.
- Which is cheaper, Claude Opus 5.5 or Muse Spark Open?
- Muse Spark Open is cheaper: $2.00 against $8.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 5.5 or Muse Spark Open?
- Muse Spark Open streams faster: 140 against 97 output tokens per second.
- Which has the larger context window?
- Muse Spark Open accepts more context: 1.0M against 1M tokens.