GPT-6 Astra vs Muse Spark Open
As of 18 Oct 2026, GPT-6 Astra (max) leads on quality (69.7 vs 61.2 on the BenchLeader Index), but Muse Spark Open (xhigh) costs 10× less, so it is the better buy unless you need the extra quality.
GPT-6 Astra 
Muse Spark Open Key differences
- GPT-6 Astra (max) leads on quality: 69.7 vs 61.2.
- GPT-6 Astra (max) is stronger in agents & tools, coding, composite, human preference, knowledge, long context, maths, multimodal, reasoning.
- Muse Spark Open (xhigh) is 10× cheaper ($2.00 vs $20.00 per 1M blended).
- Muse Spark Open (xhigh) streams 2.2× faster (140 vs 65 tokens per second).
Choose GPT-6 Astra (max) if
- reasoning is the priority (76 vs 66 on the category score)
- knowledge is the priority (79 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 $20.00 per million tokens blended
- you need fast output: 140 against 65 tokens per second
- the wait for the first word matters: 15.0 s against 285.2 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 | GPT-6 Astra (max) | Muse Spark Open (xhigh) | Leader |
|---|---|---|---|
| Reasoning | 76.2 | 65.5 | GPT-6 Astra |
| Coding | 74.2 | – | not comparable |
| Agents & tools | 64.5 | – | not comparable |
| Maths | 71.9 | – | not comparable |
| Knowledge | 79.4 | 72.5 | GPT-6 Astra |
| Human preference | 67.1 | – | not comparable |
| Multimodal | 66.2 | 64.1 | GPT-6 Astra |
| Long context | 65.4 | 64.2 | GPT-6 Astra |
| Composite | 79.8 | 73.1 | GPT-6 Astra |
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-6 Astra (max) | Muse Spark Open (xhigh) |
|---|---|---|
| Blended price per 1M tokens | $20.00 | $2.00 |
| Input / output per 1M | $10.00 / $50.00 | $1.25 / $4.25 |
| Price per task: chat reply | $0.019 | $0.0018 |
| Price per task: summarise a 30-page report | $0.150 | $0.018 |
| Price per task: code edit | $0.135 | $0.014 |
| Price per task: agentic coding session | $0.800 | $0.092 |
| Price per task: structured extraction | $0.030 | $0.0034 |
| Cost to run a full benchmark suite | $3.26 | $0.844 |
| Output speed | 65 tok/s | 140 tok/s |
| Time to first answer | 285.2 s | 15.0 s |
| Time to a complete answer | 292.9 s | 18.6 s |
Every benchmark
| Metric | GPT-6 Astra (max) | Muse Spark Open (xhigh) |
|---|---|---|
| BenchLeader Index | 69.7 | 61.2 |
| Agents & tools score | 64.5 | – |
| Coding score | 74.2 | – |
| Composite score | 79.8 | 73.1 |
| Human preference score | 67.1 | – |
| Knowledge score | 79.4 | 72.5 |
| Long context score | 65.4 | 64.2 |
| Maths score | 71.9 | – |
| Multimodal score | 66.2 | 64.1 |
| Reasoning score | 76.2 | 65.5 |
| Blended price $/M | $20.00 | $2.00 |
| Output speed | 65 tok/s | 140 tok/s |
| Time to first answer | 285.2 s | 15.0 s |
| Context window | 1.1M | 1.0M |
| GPQA Diamond | 95.8% | – |
| FrontierMath Tiers 1–3 | 93.7% | – |
| FrontierMath Tier 4 | 97.6% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 75.6% | – |
| Terminal-Bench | 58.2% | – |
| SciCode | 56.5% | – |
| WeirdML | 93.3% | – |
| FrontierCode | 53.3% | – |
| Arena Text | 1477 | – |
| Arena Hard Prompts | 1502 | – |
| Arena Coding | 1543 | – |
| Arena WebDev | 1777 | – |
| Arena Vision | 1281 | – |
| Arena Agent | 14.1 | – |
| LiveBench | 82.2% | – |
| LiveBench Reasoning | 92.7% | – |
| LiveBench Coding | 80.4% | – |
| LiveBench Agentic Coding | 57.3% | – |
| LiveBench Mathematics | 96.8% | – |
| LiveBench Data Analysis | 83.0% | – |
| LiveBench Language | 89.4% | – |
| LiveBench Instruction Following | 75.6% | – |
| AA Intelligence Index v4.3.2 | 52.7 | 38.9 |
| AA-LCR | 80.7% | 78.3% |
| MMMU-Pro | 86.9% | 80.9% |
| AA-Omniscience | 43.4 | 24.6 |
| GPQA Diamond (AA) | 96.1% | 89.0% |
| Humanity's Last Exam (AA) | 54.7% | 43.9% |
| SciCode (AA) | 56.5% | 58.5% |
| IOI | 100.0% | – |
| Terminal-Bench 2.1 (Vals) | 87.3% | – |
| Vals Index | 63.1 | 46.6 |
| ARC-AGI-1 | 97.5% | – |
| ARC-AGI-2 | 95.0% | – |
| ARC-AGI-3 | 98.6% | – |
| CritPt | 31.7% | 14.9% |
| GDPval-AA v2.1 | 53.6% | 45.1% |
| τ³-Banking (AA) | 41.4% | – |
| ITBench SRE (AA) | 48.6% | – |
| Analyst Agent (AA) | 51.3% | – |
| BioMysteryBench | 79.3% | – |
| Code Migration | 67.7% | 21.2% |
| CUA-bench | 19.2% | – |
| CyberBench | 41.1% | – |
| Excel Modeling Benchmark | 71.7% | 53.7% |
| Finance Agent v2 | 53.5% | 61.3% |
| Harvey's Legal Agent Benchmark | 5.4% | 16.7% |
| Legal Research Bench | 39.4% | 38.5% |
| MedCode | 48.5% | – |
| MedScribe | 87.9% | – |
| MysteryMechanism | 53.1% | – |
| ProgramBench | 5.5% | – |
| SAGE | 46.4% | – |
| SREBench | 56.9% | – |
| Tax Agent Bench | 20.7% | 26.3% |
| Terminal-Bench 4.0 (Vals) | 59.6% | 6.6% |
| Terminal-Bench Science | 62.9% | – |
| Time Horizon Index: KSP | 90.5% | – |
| Vibe Code Bench 1-100 | 27.6% | – |
| Vibe Code Bench v1.1 | 89.6% | 76.2% |
| DrugDiscoveryBench | 68.7% | – |
| Arena Maths | 1486 | – |
| Arena Creative Writing | 1450 | – |
| Arena Instruction Following | 1473 | – |
| Arena Multi-turn | 1486 | – |
| Arena Longer Queries | 1489 | – |
| Arena Search | 1246 | – |
| Arena Document | 1473 | – |
| Chess Puzzles | 74.0% | – |
| EBR-bench | 76.2% | – |
| Mystery Game Puzzles | 84.0% | – |
| BALROG | 68.3% | – |
| DeepSWE v1.1 | 73.2% | – |
| ALE-Bench | 2951.3 | – |
| GDP.pdf | 34.2% | – |
| FrontierSWE | 65.5% | – |
| Terminal-Bench 4.0 (AA) | 59.1% | 8.1% |
| Terminal-Bench 2.1 (AA) | 88.4% | 76.4% |
| AutomationBench | 68.5% | 49.7% |
| GDP.pdf | 31.0% | 18.6% |
| MLCR | 35.0% | – |
| Harvey LAB-AA v1.1 | 8.6% | – |
| AA-Omniscience: accuracy | 62.6% | 39.3% |
| AA-Omniscience: non-hallucination | 48.7% | 75.9% |
| AA-Briefcase v1.1 | 1569 | 1279 |
| FrontierCode 1.1 (AA) | 47.0% | – |
| Terminal-Bench-Science 0.1 (AA) | 63.3% | – |
| AA Cyber Index | 3342.0% | – |
| CWE-Bench (AA) | 63.3% | – |
| DeepSec-Bench (AA) | 36.9% | – |
| CyberGym end-to-end (AA) | 0.0% | – |
| AA-3D | 1166 | – |
| 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.
GPT-6 Astra vs Muse Spark Open: questions
- Is GPT-6 Astra better than Muse Spark Open?
- GPT-6 Astra (max) leads on quality: 69.7 vs 61.2. The BenchLeader Index combines every independent quality benchmark; GPT-6 Astra (max) is ahead overall as of 2026-10-18, but check the category scores for your use.
- Which is cheaper, GPT-6 Astra or Muse Spark Open?
- Muse Spark Open is cheaper: $2.00 against $20.00 per million tokens, blended at three input tokens per output token.
- Which is faster, GPT-6 Astra or Muse Spark Open?
- Muse Spark Open streams faster: 140 against 65 output tokens per second.
- Which has the larger context window?
- GPT-6 Astra accepts more context: 1.1M against 1.0M tokens.