BenchLeader

Claude Fable 5.1 vs DeepSeek V4.1 Flash 1017

Full profiles: Claude Fable 5.1 (Anthropic) and DeepSeek V4.1 Flash 1017 (DeepSeek): every benchmark, price and rank.

Updated · Data from 9 sources

As of 24 Oct 2026, Claude Fable 5.1 (max) leads on quality (70.5 vs 64.0 on the BenchLeader Index), but DeepSeek V4.1 Flash 1017 (max) costs 38× less, so it is the better buy unless you need the extra quality. Pick Claude Fable 5.1 for knowledge (78 vs 57); pick DeepSeek V4.1 Flash 1017 for agents & tools (63 vs 60).

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
CodingClaude Fable 5.175 vs 70 category score; Arena WebDev 1743 vs 1664Medium
Agents & tool useDeepSeek V4.1 Flash 101763 vs 60 category score; CWE-Bench (AA) 69.2% vs 50.8%Medium
MathsClaude Fable 5.173 vs 62 category score; FrontierMath Tiers 1–3 90.2% vs 71.2%High
ReasoningClaude Fable 5.177 vs 71 category score; ARC-AGI-2 90.0% vs 78.1%Medium
KnowledgeClaude Fable 5.178 vs 57 category score; SimpleQA Verified 70.8% vs 42.5%High
Long documentsClaude Fable 5.168 vs 66 category score; AA-LCR 85.3% vs 82.7%Medium
Images and other mediaClaude Fable 5.167 vs 64 category scoreMedium
Chat quality (human preference)–Only Claude Fable 5.1 has an Arena rating (70 category score)Not comparable
Lowest costDeepSeek V4.1 Flash 1017$0.525 vs $20.00 per 1M blended; agentic coding session $0.023 vs $0.800–
Fastest first answerDeepSeek V4.1 Flash 101711.2 s (DeepSeek V4.1 Flash 1017 (max)) vs 163.2 s (Claude Fable 5.1 (max)) to the first answer token–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • Claude Fable 5.1 (max) leads on quality: 70.5 vs 64.0.
  • Claude Fable 5.1 (max) is stronger in coding, composite, human preference, knowledge, long context, maths, multimodal, reasoning.
  • DeepSeek V4.1 Flash 1017 (max) is stronger in agents & tools.
  • DeepSeek V4.1 Flash 1017 (max) is 38× cheaper ($0.525 vs $20.00 per 1M blended).
  • DeepSeek V4.1 Flash 1017 (max) streams 2.9× faster (198 vs 68 tokens per second).

At a glance

SpecClaude Fable 5.1DeepSeek V4.1 Flash 1017
DeveloperAnthropicDeepSeek
Released1 Sept 202617 Oct 2026
Context window (tokens)1,000,0001,048,576
Compared atClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)
Open weightsNoYes
Price in / out / cached input per 1M$10.00 / $50.00 / $0.250$0.300 / $1.20 / $0.0060

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.

CategoryClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)Leader
Reasoning76.870.6Claude Fable 5.1
Coding75.070.1Claude Fable 5.1
Agents & tools60.263.0DeepSeek V4.1 Flash 1017
Maths72.961.8Claude Fable 5.1
Knowledge77.557.1Claude Fable 5.1
Human preference70.0–not comparable
Multimodal67.163.7Claude Fable 5.1
Long context67.866.4Claude Fable 5.1
Composite89.280.0Claude Fable 5.1

Where sources disagree

Across the 28 benchmarks both have, Claude Fable 5.1 leads 21, DeepSeek V4.1 Flash 1017 leads 7. Every overall index that rates both puts Claude Fable 5.1 ahead.

Overall indexClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)Leader
BenchLeader Index70.564.0Claude Fable 5.1
AA Intelligence Index v4.3.253.445.1Claude Fable 5.1

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.

MeasureClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)
Blended price per 1M tokens$20.00$0.525
Input / output per 1M$10.00 / $50.00$0.300 / $1.20
Cached input per 1M$0.250$0.0060
Price per task: chat reply$0.019$0.0005
Price per task: summarize a 30-page report$0.150$0.0043
Price per task: code edit$0.135$0.0036
Price per task: agentic coding session$0.800$0.023
Price per task: structured extraction$0.030$0.0008
Cost to run a full benchmark suite$7.63$0.262
Output speed68 tok/s198 tok/s
Time to first answer163.2 s11.2 s
Time to a complete answer170.6 s13.7 s

Per token is not per task: on Artificial Analysis' full suite Claude Fable 5.1 (max) cost $7.63 and DeepSeek V4.1 Flash 1017 (max) $0.262, because DeepSeek V4.1 Flash 1017 (max) used about 1.3× as many tokens for the same work, which a per-token price hides.

Each model is compared at its best-ranked reasoning-effort setting. Claude Fable 5.1 (max) scores 70.5 and takes 163 s to its first answer token; Claude Fable 5.1 (xhigh) scores 69.5 in 54 s, Claude Fable 5.1 (high) scores 69.4 in 19 s. DeepSeek V4.1 Flash 1017 (max) scores 64.0 and takes 11 s to its first answer token. 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

136 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.

MetricPublisherClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)
BenchLeader IndexBenchLeader70.564.0
Agents & tools scoreBenchLeader60.263.0
Coding scoreBenchLeader75.070.1
Composite scoreBenchLeader89.280.0
Human preference scoreBenchLeader70.0–
Knowledge scoreBenchLeader77.557.1
Long context scoreBenchLeader67.866.4
Maths scoreBenchLeader72.961.8
Multimodal scoreBenchLeader67.163.7
Reasoning scoreBenchLeader76.870.6
Blended price $/MBenchLeader$20.00$0.525
Output speedBenchLeader68 tok/s198 tok/s
Time to first answerBenchLeader163.2 s11.2 s
Context windowBenchLeader1,000,000 tokens1,048,576 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub–93.2%
Humanity's Last ExamScale AI / CAIS46.5%†–
Arena Hard PromptsArena (LMArena)1523–
LiveBench 2.0 ReasoningLiveBench91.7%†89.1%†
LiveBench 1.0 ReasoningLiveBench91.7%–
GPQA Diamond (AA)Artificial Analysis93.7%–
Humanity's Last Exam (AA)Artificial Analysis59.1%43.3%
GPQA Diamond (Vals)Vals AI93.4%†–
ARC-AGI-1ARC Prize97.5%93.5%
ARC-AGI-2ARC Prize90.0%78.1%
CritPtArtificial Analysis29.7%24.0%
MysteryMechanismVals AI47.8%†–
Chess PuzzlesEpoch AI Benchmarking Hub48.0%46.0%
Mystery Game PuzzlesEpoch AI Benchmarking Hub58.0%49.0%
LMCAEpoch AI Benchmarking Hub65.5%†–
DTBenchEpoch AI Benchmarking Hub97.6%†–
Coding
SciCodeSciCode63.1%–
WeirdMLWeirdML92.9%–
FrontierCodeCognition50.9%†–
GSO-BenchGSO-Bench88.2%†–
Arena CodingArena (LMArena)1538–
Arena WebDevArena (LMArena)17431664
LiveBench 2.0 CodingLiveBench97.7%†96.0%†
LiveBench 1.0 CodingLiveBench86.4%–
SciCode (AA)Artificial Analysis63.1%55.9%
Show all 136 benchmarks
MetricPublisherClaude Fable 5.1 (max)DeepSeek V4.1 Flash 1017 (max)
Coding
LiveCodeBenchVals AI90.5%†–
IOIVals AI90.8%†–
Code MigrationVals AI54.6%†44.2%
Code Migration v1.1Vals AI–67.5%
ProgramBenchVals AI7.0%†–
SWE-bench MultimodalVals AI61.3%†–
Vibe Code Bench 1-100Vals AI28.0%†–
Vibe Code Bench v1.1Vals AI90.3%†87.7%
SWE Atlas: Codebase QnAScale AI SEAL60.0%†–
SWE Atlas: RefactoringScale AI SEAL56.7%†–
SWE Atlas: Test WritingScale AI SEAL67.0%†–
MirrorCodeEpoch AI Benchmarking Hub73.3%†–
CursorBenchCursor51.8%–
ALE-BenchEpoch AI Benchmarking Hub2143.2†–
FrontierSWEEpoch AI Benchmarking Hub56.3%–
Terminal-Bench 4.0 (AA)Artificial Analysis52.0%33.8%
Terminal-Bench 2.1 (AA)Artificial Analysis91.4%–
Startrise FrontendStartrise77.1%†–
FrontierCode 1.1 (AA)Artificial Analysis49.0%43.7%
Agents & tools
Terminal-BenchTerminal-Bench57.9%–
Remote Labor IndexScale AI / CAIS17.9%†–
APEX-AgentsMercor68.6%†–
Arena AgentArena (LMArena)14.2–
LiveBench Long AgenticLiveBench80.8%†50.9%†
LiveBench BrowserLiveBench100.0%†76.0%†
LiveBench Agentic CodingLiveBench66.1%–
Terminal-Bench 2.1 (Vals)Vals AI85.0%†–
MCP AtlasScale AI SEAL87.2%†–
HiL-BenchScale AI SEAL61.5%†–
GDPval-AA v2.1Artificial Analysis62.7%62.3%
τ³-Banking (AA)Artificial Analysis47.2%–
ITBench SRE (AA)Artificial Analysis49.5%–
Analyst Agent (AA)Artificial Analysis57.5%–
CUA-benchVals AI13.2%–
CyberBenchVals AI70.4%†–
Finance Agent v2Vals AI58.9%†57.0%
Finance Agent v2.1Vals AI–62.9%
Harvey's Legal Agent Benchmark v1.1Vals AI–14.2%
Harvey's Legal Agent Benchmark v1Vals AI6.7%†9.2%
Legal Research BenchVals AI55.3%†45.2%
Robo-benchVals AI5.8%–
SkillsBenchVals AI61.5%†–
SREBenchVals AI22.9%†–
Tax Agent BenchVals AI49.2%†44.4%
Terminal-Bench 4.0 (Vals)Vals AI58.1%†31.8%
Terminal-Bench ScienceVals AI40.0%†–
Time Horizon Index: KSPVals AI63.3%†–
Arena SearchArena (LMArena)1233†–
Vending-Bench 2Andon Labs5421.6†–
AutomationBenchArtificial Analysis59.4%66.6%
GDP.pdf (AA)Artificial Analysis26.2%17.2%
Harvey LAB-AA v1.1Harvey6.4%–
AA-Briefcase v1.1Artificial Analysis16711570
Terminal-Bench-Science 0.1 (AA)Artificial Analysis43.3%12.9%
CWE-Bench (AA)Artificial Analysis50.8%69.2%
DeepSec-Bench (AA)Artificial Analysis23.5%24.9%
CyberGym end-to-end (AA)Artificial Analysis0.8%76.3%
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub90.2%71.2%
FrontierMath Tier 4Epoch AI Benchmarking Hub87.8%46.3%
OTIS Mock AIMEEpoch AI Benchmarking Hub100.0%99.4%
ProofBenchVals AI100.0%–
LiveBench MathematicsLiveBench97.0%–
Arena MathsArena (LMArena)1529–
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub70.8%42.5%
LiveBench 2.0 Data AnalysisLiveBench80.3%†79.5%†
LiveBench ResearchLiveBench82.0%†79.5%†
LiveBench 1.0 Data AnalysisLiveBench80.3%–
AA-OmniscienceArtificial Analysis43.54.7
MMLU-ProVals AI92.4%†–
LegalBenchVals AI88.5%†–
TaxEvalVals AI76.0%†–
PRBench FinanceScale AI SEAL50.8%†–
PRBench LegalScale AI SEAL51.6%†–
Excel Modeling BenchmarkVals AI76.7%†61.8%
Excel Modeling Benchmark v1.1Vals AI76.7%†69.2%
MedCodeVals AI53.5%†–
MedScribeVals AI91.3%†–
Public Benefits Bench v1.1Vals AI74.9%†–
EBR-benchEpoch AI Benchmarking Hub57.1%–
GDP.pdfEpoch AI Benchmarking Hub27.6%–
AA-Omniscience: accuracyArtificial Analysis67.2%42.9%
AA-Omniscience: non-hallucinationArtificial Analysis27.4%33.3%
Instruction following
LiveBench LanguageLiveBench89.5%–
LiveBench Instruction FollowingLiveBench73.0%–
Arena Instruction FollowingArena (LMArena)1501–
Human preference
Arena TextArena (LMArena)1503–
Arena Creative WritingArena (LMArena)1487–
Arena Multi-turnArena (LMArena)1488–
Arena Longer QueriesArena (LMArena)1511–
Multimodal
Arena VisionArena (LMArena)1320–
LiveBench DesignLiveBench83.4%†83.4%†
MMMU-ProArtificial Analysis–80.6%
MMMU-Pro (Vals)Vals AI90.6%†–
MortgageTaxVals AI70.8%†–
SAGEVals AI48.5%†–
Blueprint-Bench 2Epoch AI Benchmarking Hub41.9%†–
AA-3DArtificial Analysis1133–
Long context
AA-LCRArtificial Analysis85.3%82.7%
Arena DocumentArena (LMArena)1493–
MLCRArtificial Analysis15.6%26.7%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub166.5†–
LiveBench 2.0LiveBench88.0%†79.2%†
LiveBench 1.0LiveBench83.4%–
AA Intelligence Index v4.3.2Artificial Analysis53.445.1
Vals IndexVals AI–61.3
Vals Finance IndexVals AI–60.9%
Vals RSI IndexVals AI36.1%–
Vals Router IndexVals AI–61.3%†
AA Cyber IndexArtificial Analysis25.056.8
Safety & honesty
FORTRESSScale AI SEAL13.7%†–
Metadata
AA Openness IndexArtificial Analysis–44.4

Data as of 2026-10-24. Best configuration of each model; every score links to its source on the model pages.

What changed

  • Claude Fable 5.1 (max): 2 new results (Robo-bench, Vals RSI Index).
  • DeepSeek V4.1 Flash 1017 (max): 10 new results (MLCR, AA Cyber Index, CWE-Bench (AA)…).
  • DeepSeek V4.1 Flash 1017 (max): BenchLeader Index 63.1 → 63.9.
  • Claude Fable 5.1 (max): 1 score revision.
  • DeepSeek V4.1 Flash 1017 (max): 11 new results (GPQA Diamond, FrontierMath Tiers 1–3, FrontierMath Tier 4…).
  • Claude Fable 5.1 (max): 1 score revision.
  • DeepSeek V4.1 Flash 1017 (max): 1 new result (FrontierCode 1.1 (AA)); 2 score revisions.
  • Claude Fable 5.1 (max): BenchLeader Index 70.0 → 70.6.
  • Claude Fable 5.1 (max): 2 score revisions.
  • Claude Fable 5.1 (max): 1 score revision.

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

Claude Fable 5.1 vs DeepSeek V4.1 Flash 1017: questions

Is Claude Fable 5.1 better than DeepSeek V4.1 Flash 1017?
Claude Fable 5.1 (max) leads on quality: 70.5 vs 64.0. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 (max) is ahead overall as of 2026-10-24, but check the category scores for your use.
Which is cheaper, Claude Fable 5.1 or DeepSeek V4.1 Flash 1017, and will that change?
DeepSeek V4.1 Flash 1017 is cheaper today: $0.525 against $20.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is Claude Fable 5.1 better than DeepSeek V4.1 Flash 1017 for coding?
Claude Fable 5.1 scores higher in coding (75 vs 70 on the category index, where 50 is average). On Arena WebDev, the top shared coding benchmark, it is 1743 for Claude Fable 5.1 against 1664 for DeepSeek V4.1 Flash 1017.
Is Claude Fable 5.1 better than DeepSeek V4.1 Flash 1017 for agents and tool use?
DeepSeek V4.1 Flash 1017 scores higher in agentic tasks (63 vs 60 on the category index, where 50 is average). On CWE-Bench (AA), the top shared agents & tools benchmark, it is 50.8% for Claude Fable 5.1 against 69.2% for DeepSeek V4.1 Flash 1017.
Which is better for long documents?
Claude Fable 5.1 scores higher on long-context benchmarks (68 vs 66). Both take about 1M tokens: Claude Fable 5.1 1,000,000, DeepSeek V4.1 Flash 1017 1,048,576.
Which has lower latency?
DeepSeek V4.1 Flash 1017 (max) answers first: 11.2 s against 163.2 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
Which is faster, Claude Fable 5.1 or DeepSeek V4.1 Flash 1017?
DeepSeek V4.1 Flash 1017 streams faster: 198 against 68 output tokens per second.
Do independent benchmarks agree on Claude Fable 5.1 vs DeepSeek V4.1 Flash 1017?
Across the 28 benchmarks both have, Claude Fable 5.1 leads 21, DeepSeek V4.1 Flash 1017 leads 7. Every overall index that rates both puts Claude Fable 5.1 ahead.
When was DeepSeek V4.1 Flash 1017 released?
DeepSeek V4.1 Flash 1017 was released on 17 Oct 2026.