Claude Opus 5 vs Muse Spark Open
As of 18 Oct 2026, Claude Opus 5 (high) leads on quality (68.0 vs 61.2 on the BenchLeader Index), but Muse Spark Open (xhigh) costs 5.0× less, so it is the better buy unless you need the extra quality.
Claude Opus 5 
Muse Spark Open Key differences
- Claude Opus 5 (high) leads on quality: 68.0 vs 61.2.
- Claude Opus 5 (high) is stronger in agents & tools, coding, composite, human preference, knowledge, long context, maths, multimodal, reasoning.
- Muse Spark Open (xhigh) is 5.0× cheaper ($2.00 vs $10.00 per 1M blended).
- Muse Spark Open (xhigh) streams 2.5× faster (140 vs 55 tokens per second).
Choose Claude Opus 5 (high) if
- reasoning is the priority (72 vs 66 on the category score)
- knowledge is the priority (77 vs 73 on the category score)
- multimodal is the priority (66 vs 64 on the category score)
Choose Muse Spark Open (xhigh) if
- cost matters: $2.00 against $10.00 per million tokens blended
- you need fast output: 140 against 55 tokens per second
- 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 (high) | Muse Spark Open (xhigh) | Leader |
|---|---|---|---|
| Reasoning | 72.3 | 65.5 | Claude Opus 5 |
| Coding | 69.0 | – | not comparable |
| Agents & tools | 65.2 | – | not comparable |
| Maths | 71.1 | – | not comparable |
| Knowledge | 76.6 | 72.5 | Claude Opus 5 |
| Human preference | 68.7 | – | not comparable |
| Multimodal | 66.4 | 64.1 | Claude Opus 5 |
| Long context | 64.5 | 64.2 | level |
| Composite | 83.5 | 73.1 | Claude Opus 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 (high) | Muse Spark Open (xhigh) |
|---|---|---|
| Blended price per 1M tokens | $10.00 | $2.00 |
| Input / output per 1M | $5.00 / $25.00 | $1.25 / $4.25 |
| Price per task: chat reply | $0.0095 | $0.0018 |
| Price per task: summarise a 30-page report | $0.075 | $0.018 |
| Price per task: code edit | $0.068 | $0.014 |
| Price per task: agentic coding session | $0.400 | $0.092 |
| Price per task: structured extraction | $0.015 | $0.0034 |
| Cost to run a full benchmark suite | $3.61 | $0.844 |
| Output speed | 55 tok/s | 140 tok/s |
| Time to first answer | 18.8 s | 15.0 s |
| Time to a complete answer | 27.8 s | 18.6 s |
Every benchmark
| Metric | Claude Opus 5 (high) | Muse Spark Open (xhigh) |
|---|---|---|
| BenchLeader Index | 68.0 | 61.2 |
| Agents & tools score | 65.2 | – |
| Coding score | 69.0 | – |
| Composite score | 83.5 | 73.1 |
| Human preference score | 68.7 | – |
| Knowledge score | 76.6 | 72.5 |
| Long context score | 64.5 | 64.2 |
| Maths score | 71.1 | – |
| Multimodal score | 66.4 | 64.1 |
| Reasoning score | 72.3 | 65.5 |
| Blended price $/M | $10.00 | $2.00 |
| Output speed | 55 tok/s | 140 tok/s |
| Time to first answer | 18.8 s | 15.0 s |
| Context window | 1M | 1.0M |
| Terminal-Bench | 50.3% | – |
| OSWorld-Verified 2.0 | 29.0% | – |
| SciCode | 54.3% | – |
| WeirdML | 91.6% | – |
| Arena Text | 1490 | – |
| Arena Hard Prompts | 1514 | – |
| Arena Coding | 1533 | – |
| Arena WebDev | 1657 | – |
| Arena Vision | 1319 | – |
| AA Intelligence Index v4.3.2 | 48.1 | 38.9 |
| AA-LCR | 79.0% | 78.3% |
| MMMU-Pro | 82.4% | 80.9% |
| AA-Omniscience | 33.7 | 24.6 |
| GPQA Diamond (AA) | 93.7% | 89.0% |
| Humanity's Last Exam (AA) | 52.8% | 43.9% |
| SciCode (AA) | 55.4% | 58.5% |
| Vals Index | – | 46.6 |
| ARC-AGI-1 | 97.5% | – |
| ARC-AGI-2 | 88.3% | – |
| ARC-AGI-3 | 30.2% | – |
| CritPt | 28.3% | 14.9% |
| GDPval-AA v2.1 | 54.8% | 45.1% |
| τ³-Banking (AA) | 44.7% | – |
| Code Migration | – | 21.2% |
| 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% |
| Arena Maths | 1522 | – |
| Arena Creative Writing | 1471 | – |
| Arena Instruction Following | 1496 | – |
| Arena Multi-turn | 1484 | – |
| Arena Longer Queries | 1503 | – |
| Arena Search | 1214 | – |
| Arena Document | 1490 | – |
| DeepSWE v1.1 | 72.8% | – |
| LMCA | 63.7% | – |
| DTBench | 97.9% | – |
| CursorBench | 44.7% | – |
| ALE-Bench | 2164.6 | – |
| Terminal-Bench 4.0 (AA) | 46.0% | 8.1% |
| Terminal-Bench 2.1 (AA) | 87.6% | 76.4% |
| AutomationBench | 53.6% | 49.7% |
| GDP.pdf | 19.6% | 18.6% |
| MLCR | 59.4% | – |
| AA-Omniscience: accuracy | 58.9% | 39.3% |
| AA-Omniscience: non-hallucination | 38.8% | 75.9% |
| AA-Briefcase v1.1 | 1561 | 1279 |
| 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 vs Muse Spark Open: questions
- Is Claude Opus 5 better than Muse Spark Open?
- Claude Opus 5 (high) leads on quality: 68.0 vs 61.2. The BenchLeader Index combines every independent quality benchmark; Claude Opus 5 (high) is ahead overall as of 2026-10-18, but check the category scores for your use.
- Which is cheaper, Claude Opus 5 or Muse Spark Open?
- Muse Spark Open is cheaper: $2.00 against $10.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 5 or Muse Spark Open?
- Muse Spark Open streams faster: 140 against 55 output tokens per second.
- Which has the larger context window?
- Muse Spark Open accepts more context: 1.0M against 1M tokens.