BenchLeader

GPT-5.6 Sol vs Muse Spark Open 816B A42B

Full profiles: GPT-5.6 Sol (OpenAI) and Muse Spark Open 816B A42B (Meta): every benchmark, price and rank.

Updated · Data from 9 sources

As of 29 Oct 2026, GPT-5.6 Sol is ahead of Muse Spark Open 816B A42B on quality (65.4 vs 58.5 on the BenchLeader Index), but Muse Spark Open 816B A42B is 4.0× cheaper at $2.00 vs $8.00 per 1M tokens blended. GPT-5.6 Sol leads in every category we measure both in.

Key facts (as of 29 Oct 2026)

  • GPT-5.6 Sol scores 65.4 on the BenchLeader Index and Muse Spark Open 816B A42B scores 58.5 (BenchLeader, 29 Oct 2026).
  • GPT-5.6 Sol costs $8.00 per 1M tokens blended (list price, 29 Oct 2026).
  • Muse Spark Open 816B A42B costs $2.00 per 1M tokens blended (list price, 29 Oct 2026).
  • Of the 7 benchmarks both models have, GPT-5.6 Sol leads 6 (BenchLeader, 29 Oct 2026).

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 casePickWhyConfidence
CodingEither66 vs 66 category score; SciCode 57.1% vs 58.5%Either
MathsGPT-5.6 Sol71 vs 59 category score; FrontierMath Tiers 1–3 89.1% vs 69.8%High
ReasoningGPT-5.6 Sol65 vs 64 category score; GPQA Diamond 93.5% vs 88.6%Medium
KnowledgeGPT-5.6 Sol64 vs 62 category score; SimpleQA Verified 69.7% vs 56.6%Medium
Lowest costMuse Spark Open 816B A42B$2.00 vs $8.00 per 1M blended; agentic coding session $0.092 vs $0.320–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • GPT-5.6 Sol (max) leads on quality: 65.4 vs 58.5.
  • GPT-5.6 Sol (max) is stronger in agents & tools, coding, instruction following, knowledge, long context, maths, multimodal, reasoning.
  • Muse Spark Open 816B A42B (xhigh) is 4.0× cheaper ($2.00 vs $8.00 per 1M blended).

At a glance

SpecGPT-5.6 SolMuse Spark Open 816B A42B
DeveloperOpenAIMeta
Released9 Jul 202615 Oct 2026
Context window (tokens)1,050,0001,048,576
Compared atGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)
Open weightsNoYes
Price in / out / cached input per 1M$4.00 / $20.00 / $0.400$1.25 / $4.25 / $0.150

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.

CategoryGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)Leader
Reasoning65.163.6GPT-5.6 Sol
Coding65.865.5level
Agents & tools66.6–not comparable
Maths70.859.4GPT-5.6 Sol
Knowledge63.962.2GPT-5.6 Sol
Instruction following71.1–not comparable
Multimodal66.2–not comparable
Long context66.9–not comparable

Where sources disagree

Across the 7 benchmarks both have, GPT-5.6 Sol leads 6, Muse Spark Open 816B A42B leads 1. Every overall index that rates both puts GPT-5.6 Sol ahead.

Overall indexGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)Leader
BenchLeader Index65.458.5GPT-5.6 Sol

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.

MeasureGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)
Blended price per 1M tokens$8.00$2.00
Input / output per 1M$4.00 / $20.00$1.25 / $4.25
Cached input per 1M$0.400$0.150
Price per task: chat reply$0.0076$0.0018
Price per task: summarize 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
Output speed85 tok/s–
Time to first answer86.2 s–
Time to a complete answer92.1 s–

Each model is compared at its best-ranked reasoning-effort setting. GPT-5.6 Sol (max) scores 65.4 and takes 86 s to its first answer token; GPT-5.6 Sol (xhigh) scores 64.2 in 22 s, GPT-5.6 Sol (high) scores 63.6 in 11 s. Muse Spark Open 816B A42B (xhigh) scores 58.5. 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

130 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.

MetricPublisherGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)
BenchLeader IndexBenchLeader65.458.5
Agents & tools scoreBenchLeader66.6–
Coding scoreBenchLeader65.865.5
Instruction following scoreBenchLeader71.1–
Knowledge scoreBenchLeader63.962.2
Long context scoreBenchLeader66.9–
Maths scoreBenchLeader70.859.4
Multimodal scoreBenchLeader66.2–
Reasoning scoreBenchLeader65.163.6
Blended price $/MBenchLeader$8.00$2.00
Output speedBenchLeader85 tok/s–
Time to first answerBenchLeader86.2 s–
Context windowBenchLeader1,050,000 tokens1,048,576 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub93.5%88.6%
SimpleBenchSimpleBench64.8%†–
Arena Hard PromptsArena (LMArena)1511†–
LiveBench 1.0 ReasoningLiveBench91.7%–
GPQA Diamond (AA)Artificial Analysis94.1%–
Humanity's Last Exam (AA)Artificial Analysis49.5%–
GPQA Diamond (Vals)Vals AI95.2%–
EnigmaEvalScale AI SEAL37.1%†–
Kagi LLM BenchmarkKagi LLM Benchmark67.0%†–
ARC-AGI-1ARC Prize96.5%–
ARC-AGI-2ARC Prize92.5%–
ARC-AGI-3ARC Prize7.8%–
CritPtArtificial Analysis32.3%–
CritPt v2 hard subset (AA)Artificial Analysis56.0%–
MysteryMechanismVals AI33.3%–
Chess PuzzlesEpoch AI Benchmarking Hub59.0%–
Mystery Game PuzzlesEpoch AI Benchmarking Hub58.0%–
LMCAEpoch AI Benchmarking Hub58.4%–
DTBenchEpoch AI Benchmarking Hub95.5%–
ForecastBenchForecastBench65.5%–
BTF-3Epoch AI Benchmarking Hub13.7%–
Coding
SciCodeSciCode57.1%58.5%
WeirdMLWeirdML87.0%–
FrontierCodeCognition47.5%†–
GSO-BenchGSO-Bench76.5%†–
Show all 130 benchmarks
MetricPublisherGPT-5.6 Sol (max)Muse Spark Open 816B A42B (xhigh)
Coding
Arena CodingArena (LMArena)1533†–
Arena WebDevArena (LMArena)1616†–
LiveBench 1.0 CodingLiveBench83.9%–
SciCode (AA)Artificial Analysis57.1%–
LiveCodeBenchVals AI82.6%–
IOIVals AI91.2%–
SWE-bench (Vals)Vals AI96.2%–
Code MigrationVals AI52.9%–
ProgramBenchVals AI1.5%–
Vibe Code Bench 1-100Vals AI20.0%–
Vibe Code Bench v1.1Vals AI80.5%–
SWE Atlas: Codebase QnAScale AI SEAL46.0%†–
SWE Atlas: Test WritingScale AI SEAL45.9%†–
MirrorCodeEpoch AI Benchmarking Hub20.0%†–
Surface Evolver BenchEpoch AI Benchmarking Hub93.1%†–
DeepSWE v1.1Epoch AI Benchmarking Hub72.7%–
CursorBenchCursor41.7%–
ALE-BenchEpoch AI Benchmarking Hub2176.91590.1
FrontierSWEEpoch AI Benchmarking Hub32.2%–
Terminal-Bench 4.0 (AA)Artificial Analysis39.9%–
Terminal-Bench 2.1 (AA)Artificial Analysis88.0%–
Startrise FrontendStartrise66.2%†–
Agents & tools
Terminal-BenchTerminal-Bench37.3%–
OSWorld-Verified 2.0OSWorld27.3%–
APEX-AgentsMercor–33.4%†
Arena AgentArena (LMArena)4.8†–
LiveBench Agentic CodingLiveBench56.2%–
Terminal-Bench HardArtificial Analysis65.9%–
τ²-Bench Telecom (AA)Artificial Analysis85.1%–
Terminal-Bench 2.1 (Vals)Vals AI85.8%–
HiL-BenchScale AI SEAL32.3%†–
τ³-bench Bankingτ²-bench46.9%†–
τ³-Banking (AA)Artificial Analysis44.3%–
ITBench SRE (AA)Artificial Analysis56.2%–
Analyst Agent (AA)Artificial Analysis47.5%–
CUA-benchVals AI8.3%–
CyberBenchVals AI76.3%–
Finance Agent v2Vals AI53.8%–
Harvey's Legal Agent Benchmark v1Vals AI2.5%–
Legal Research BenchVals AI48.1%–
SkillsBenchVals AI54.1%–
SREBenchVals AI30.5%–
Tax Agent BenchVals AI31.1%–
Terminal-Bench 4.0 (Vals)Vals AI37.9%–
Terminal-Bench ScienceVals AI20.0%–
Time Horizon Index: KSPVals AI23.8%–
Web Search IndexVals AI43.6%–
Arena SearchArena (LMArena)1258†–
BALROGBALROG60.0%–
PostTrainBenchEpoch AI Benchmarking Hub36.2%–
GBAEvalEpoch AI Benchmarking Hub52.6%†–
Vending-Bench 2Andon Labs9619.4†–
AutomationBenchArtificial Analysis60.1%–
GDP.pdf (AA)Artificial Analysis27.2%–
EnterpriseOps-GymArtificial Analysis42.9%–
AA-Briefcase v1.1Artificial Analysis1478–
Terminal-Bench-Science 0.1 (AA)Artificial Analysis22.4%–
FACTS SearchGoogle88.5%†–
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub89.1%69.8%
FrontierMath Tier 4Epoch AI Benchmarking Hub82.9%31.7%
OTIS Mock AIMEEpoch AI Benchmarking Hub100.0%98.1%
ProofBenchVals AI83.0%–
LiveBench MathematicsLiveBench96.2%–
Arena MathsArena (LMArena)1495†–
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub69.7%56.6%
LiveBench 1.0 Data AnalysisLiveBench79.8%–
MMLU-ProVals AI89.1%–
LegalBenchVals AI87.0%–
CorpFinVals AI64.4%–
TaxEvalVals AI74.8%–
PRBench FinanceScale AI SEAL50.5%–
PRBench LegalScale AI SEAL50.5%–
BioMysteryBenchVals AI71.1%–
Excel Modeling BenchmarkVals AI72.3%–
MedCodeVals AI44.0%–
MedScribeVals AI85.2%–
Public Benefits Bench v1.1Vals AI66.5%–
DrugDiscoveryBenchScale AI SEAL56.5%–
EBR-benchEpoch AI Benchmarking Hub44.8%–
GDP.pdfEpoch AI Benchmarking Hub30.7%–
Instruction following
LiveBench LanguageLiveBench87.7%–
LiveBench Instruction FollowingLiveBench71.8%–
IFBenchArtificial Analysis72.7%–
Arena Instruction FollowingArena (LMArena)1491†–
Human preference
Arena TextArena (LMArena)1485†–
EQ-Bench 4EQ-Bench1236†–
Arena Creative WritingArena (LMArena)1470†–
Arena Multi-turnArena (LMArena)1490†–
Arena Longer QueriesArena (LMArena)1498†–
Multimodal
Arena VisionArena (LMArena)1281†–
MMMU-ProArtificial Analysis83.4%–
MMMU-Pro (Vals)Vals AI88.8%–
MortgageTaxVals AI67.3%–
Blueprint-Bench 2Epoch AI Benchmarking Hub33.6%†–
Long context
AA-LCR v1.1Artificial Analysis84.0%–
Arena DocumentArena (LMArena)1489†–
MLCRArtificial Analysis30.0%–
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub162.7†–
LiveBench 1.0LiveBench81.0%–
AA Intelligence Index v4.3.2Artificial Analysis47.0–
AA Progress Index v1Artificial Analysis331.5–
Vals RSI IndexVals AI23.9%–
Vals Science IndexVals AI41.5%–
Vals Multimodal IndexVals AI72.6%–
Safety & honesty
FORTRESSScale AI SEAL20.1%†–

Data as of 2026-10-29. Best configuration of each model; every score links to its source on the model pages.

What changed

  • GPT-5.6 Sol (max): 2 new results (AA Progress Index v1, CritPt v2 hard subset (AA)).
  • GPT-5.6 Sol (max): 1 new result (AA-Briefcase v1.1).
  • GPT-5.6 Sol (max): 3 new results (Harvey's Legal Agent Benchmark v1, Vals RSI Index, Vals Science Index).
  • GPT-5.6 Sol (max): 1 score revision.
  • GPT-5.6 Sol (max): 1 new result (ForecastBench).
  • Muse Spark Open 816B A42B (xhigh): BenchLeader Index 57.4 → 58.6.
  • Muse Spark Open 816B A42B (xhigh): 2 new results (SciCode, ALE-Bench).
  • GPT-5.6 Sol (max): 5 new results (AutomationBench, GDP.pdf (AA), MLCR…).
  • Muse Spark Open 816B A42B (xhigh): first results.
  • GPT-5.6 Sol (max): 1 score revision.

Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs

GPT-5.6 Sol vs Muse Spark Open 816B A42B: questions

Is GPT-5.6 Sol better than Muse Spark Open 816B A42B?
GPT-5.6 Sol (max) leads on quality: 65.4 vs 58.5. The BenchLeader Index combines every independent quality benchmark; GPT-5.6 Sol (max) is ahead overall as of 29 Oct 2026, but check the category scores for your use.
GPT-5.6 Sol vs Muse Spark Open 816B A42B: which is cheaper, and will that change?
Muse Spark Open 816B A42B is cheaper today: $2.00 against $8.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is GPT-5.6 Sol or Muse Spark Open 816B A42B better for coding?
They are level in coding (66 vs 66 on the category index). On SciCode, the top shared coding benchmark, it is 57.1% for GPT-5.6 Sol against 58.5% for Muse Spark Open 816B A42B.
Which is better for long documents?
Both take about 1.1M tokens: GPT-5.6 Sol 1,050,000, Muse Spark Open 816B A42B 1,048,576.
Do independent benchmarks agree on GPT-5.6 Sol vs Muse Spark Open 816B A42B?
Across the 7 benchmarks both have, GPT-5.6 Sol leads 6, Muse Spark Open 816B A42B leads 1. Every overall index that rates both puts GPT-5.6 Sol ahead.
More questions (1)
When was Muse Spark Open 816B A42B released?
Muse Spark Open 816B A42B was released on 15 Oct 2026.