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Claude Fable 5.1 vs Inkling 2 Small

Full profiles: Claude Fable 5.1 (Anthropic) and Inkling 2 Small (Thinking Machines): every benchmark, price and rank.

Updated · Data from 13 sources

As of 13 Nov 2026, Claude Fable 5.1 is ahead of Inkling 2 Small on quality (66.6 vs 57.9 on the BenchLeader Index), but Inkling 2 Small is 42× cheaper at $0.475 vs $20.00 per 1M tokens blended. Claude Fable 5.1 leads in every category we measure both in. Inkling 2 Small streams ~1.5× faster.

Key facts (as of 13 Nov 2026)

  • Claude Fable 5.1 scores 66.6 on the BenchLeader Index and Inkling 2 Small scores 57.9 (BenchLeader, 13 Nov 2026).
  • Claude Fable 5.1 costs $20.00 per 1M tokens blended (list price, 13 Nov 2026).
  • Inkling 2 Small costs $0.475 per 1M tokens blended (list price, 13 Nov 2026).
  • Inkling 2 Small streams ~1.5× faster than Claude Fable 5.1 (Artificial Analysis, 7-day median, 13 Nov 2026).
  • Of the 28 benchmarks both models have, Claude Fable 5.1 leads 26 (BenchLeader, 13 Nov 2026).
  • On Arena WebDev, Claude Fable 5.1 is rated 1742 and Inkling 2 Small 1647 (LMArena, as published by 13 Nov 2026).
Claude Fable 5.1 benchmarks max Anthropic Inkling 2 Small benchmarks Thinking MachinesAdd a third model

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 5.171 vs 60 category score; Arena WebDev 1742 vs 1647High
Agents & tool useEither60 vs 61 category score; τ³-Banking (AA) 47.2% vs 40.4%Either
ReasoningClaude Fable 5.169 vs 53 category score; HLE-Diamond (AA) 60.1% vs 28.7%High
KnowledgeClaude Fable 5.171 vs 54 category score; AA-Omniscience v1.1 46.3 vs 16.1High
Long documentsClaude Fable 5.167 vs 66 category score; AA-LCR v1.1 85.3% vs 83.3%Medium
Images and other mediaClaude Fable 5.168 vs 64 category score; Code2Video-AA 1325 vs 1020Medium
Chat quality (human preference)Claude Fable 5.170 vs 59 on Arena votesHigh
Lowest costInkling 2 Small$0.475 vs $20.00 per 1M blended; agentic coding session $0.022 vs $0.800–
Fastest first answerInkling 2 Small63.9 s (Inkling 2 Small) vs 162.2 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: 66.6 vs 57.9.
  • Claude Fable 5.1 (max) is stronger in coding, human preference, knowledge, long context, multimodal, reasoning.
  • Inkling 2 Small is stronger in agents & tools.
  • Inkling 2 Small is 42× cheaper ($0.475 vs $20.00 per 1M blended).

At a glance

SpecClaude Fable 5.1Inkling 2 Small
DeveloperAnthropicThinking Machines
Released1 Sep 20265 Nov 2026
Context window (tokens)1,000,0001,048,576
Compared atClaude Fable 5.1 (max)Inkling 2 Small
Open weightsNoNo
Price in / out / cached input per 1M$10.00 / $50.00 / $0.250$0.300 / $1.00 / –

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)Inkling 2 SmallLeader
Reasoning69.352.8Claude Fable 5.1
Coding70.560.3Claude Fable 5.1
Agents & tools60.261.1level
Maths72.0–not comparable
Knowledge71.453.5Claude Fable 5.1
Human preference69.758.6Claude Fable 5.1
Multimodal67.564.0Claude Fable 5.1
Long context67.466.4Claude Fable 5.1

On one chart

Each domain on the index's own scale, where 50 is an average model. Click a domain to see the benchmarks behind it. Pick up to 5 models from the list.

2550 avg75ReasoningCodingAgents & toolsKnowledgeLong contextMultimodalHumanpreferenceClaude Fable 5.1, Reasoning: 69.3Claude Fable 5.1, Coding: 70.5Claude Fable 5.1, Agents & tools: 60.2Claude Fable 5.1, Knowledge: 71.4Claude Fable 5.1, Long context: 67.4Claude Fable 5.1, Multimodal: 67.5Claude Fable 5.1, Human preference: 69.7Inkling 2 Small, Reasoning: 52.8Inkling 2 Small, Coding: 60.3Inkling 2 Small, Agents & tools: 61.1Inkling 2 Small, Knowledge: 53.5Inkling 2 Small, Long context: 66.4Inkling 2 Small, Multimodal: 64.0Inkling 2 Small, Human preference: 58.6

Not drawn, measured for fewer than two of these models: Maths, Instruction following.

Model, click to add or removeIndex

Where sources disagree

Across the 28 benchmarks both have, Claude Fable 5.1 leads 26, Inkling 2 Small leads 2. Every overall index that rates both puts Claude Fable 5.1 ahead.

Overall indexClaude Fable 5.1 (max)Inkling 2 SmallLeader
BenchLeader Index66.657.9Claude Fable 5.1
AA Intelligence Index v5.049.230.6Claude Fable 5.1
Arena Text15021412Claude 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. Cost, tokens and time per benchmark task are measured: Artificial Analysis’ averages over its whole Intelligence Index run.

MeasureClaude Fable 5.1 (max)Inkling 2 Small
Blended price per 1M tokens$20.00$0.475
Input / output per 1M$10.00 / $50.00$0.300 / $1.00
Cached input per 1M$0.250–
Price per task: chat reply$0.019$0.0004
Price per task: summarize a 30-page report$0.150$0.0042
Price per task: code edit$0.135$0.0033
Price per task: agentic coding session$0.800$0.022
Price per task: structured extraction$0.030$0.0008
Agentic coding session, input mostly cached$0.361–
Cost per benchmark task (AA Index)$12.99$1.18
Output tokens per task (AA Index)118k150k
Of which reasoning71k88k
Time per task (AA Index)22 min28 min
Output speed88 tok/s90 tok/s
Time to first answer162.2 s63.9 s
Time to a complete answer386.7 s163.6 s

Per token is not per task: an average task of Artificial Analysis' Intelligence Index cost $12.99 on Claude Fable 5.1 (max) and $1.18 on Inkling 2 Small, and Inkling 2 Small wrote 1.3× as many output tokens for the same work.

Each model is compared at its best-ranked reasoning-effort setting. Claude Fable 5.1 (max) scores 66.6 and takes 162 s to its first answer token; Claude Fable 5.1 scores 66.4 in 3 s, Claude Fable 5.1 (xhigh) scores 64.6 in 48 s. Inkling 2 Small scores 57.9 and takes 64 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

152 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)Inkling 2 Small
BenchLeader IndexBenchLeader66.657.9
Agents & tools scoreBenchLeader60.261.1
Coding scoreBenchLeader70.560.3
Human preference scoreBenchLeader69.758.6
Knowledge scoreBenchLeader71.453.5
Long context scoreBenchLeader67.466.4
Maths scoreBenchLeader72.0–
Multimodal scoreBenchLeader67.564.0
Reasoning scoreBenchLeader69.352.8
Blended price $/MBenchLeader$20.00$0.475
Output speedBenchLeader88 tok/s90 tok/s
Time to first answerBenchLeader162.2 s63.9 s
Context windowBenchLeader1,000,000 tokens1,048,576 tokens
Reasoning
Humanity's Last ExamScale AI / CAIS46.5%†–
SimpleBenchSimpleBench86.6%†–
Arena Hard PromptsArena (LMArena)15221438
LiveBench 2.0 ReasoningLiveBench91.7%†–
LiveBench 1.0 ReasoningLiveBench91.7%–
GPQA Diamond (AA)Artificial Analysis93.7%–
Humanity's Last Exam (AA)Artificial Analysis59.1%44.1%
HLE-Diamond (AA)Artificial Analysis60.1%28.7%
GPQA Diamond (Vals)Vals AI93.4%†–
ARC-AGI-1ARC Prize97.5%96.5%†
ARC-AGI-2ARC Prize90.0%81.7%†
CritPtArtificial Analysis29.7%–
CritPt v2 hard subset (AA)Artificial Analysis52.5%35.0%
MysteryMechanismVals AI47.8%†25.2%
Chess PuzzlesEpoch AI Benchmarking Hub48.0%–
Mystery Game PuzzlesEpoch AI Benchmarking Hub58.0%–
LMCAEpoch AI Benchmarking Hub65.5%†–
DTBenchEpoch AI Benchmarking Hub97.6%†–
ForecastBenchForecastBench65.7%†–
Coding
SciCodeSciCode63.1%52.3%
WeirdMLWeirdML92.9%–
FrontierCodeCognition50.9%†–
GSO-BenchGSO-Bench88.2%†–
Arena CodingArena (LMArena)15341485
Arena WebDevArena (LMArena)17421647
Show all 152 benchmarks
MetricPublisherClaude Fable 5.1 (max)Inkling 2 Small
Coding
LiveBench 2.0 CodingLiveBench89.7%†–
LiveBench 1.0 CodingLiveBench86.4%–
LiveCodeBenchVals AI90.5%†–
IOIVals AI90.8%†–
Code MigrationVals AI54.6%†–
ProgramBenchVals AI7.0%†0.5%
SWE-bench MultimodalVals AI61.3%†43.1%
Vibe Code Bench 1-100Vals AI28.0%†–
Vibe Code Bench v1.1Vals AI90.3%†81.5%
SWE Atlas: Codebase QnAScale AI SEAL60.0%†–
SWE Atlas: RefactoringScale AI SEAL56.7%†–
SWE Atlas: Test WritingScale AI SEAL67.0%†–
MirrorCodeEpoch AI Benchmarking Hub93.3%–
CursorBenchCursor51.8%–
ALE-BenchEpoch AI Benchmarking Hub2143.2†–
FrontierSWEEpoch AI Benchmarking Hub56.3%–
Terminal-Bench 4.0 (AA)Artificial Analysis52.0%13.1%
Terminal-Bench 2.1 (AA)Artificial Analysis91.4%81.3%
Startrise FrontendStartrise77.1%†–
GameBench 2 OverallDuelLab GameBench 287.2†–
GameBench 2 by reasoning settingDuelLab GameBench 293.9†–
Design Arena WebsiteDesign Arena1305†1335
FrontierCode 1.1 (AA)Artificial Analysis49.0%–
FrontierCode 2.0 (AA)Artificial Analysis31.6%25.4%
Agents & tools
Terminal-BenchTerminal-Bench57.3%13.0%†
Remote Labor IndexScale AI / CAIS17.9%†–
APEX-AgentsMercor68.6%†46.8%
Arena AgentArena (LMArena)14.82.5
LiveBench Long AgenticLiveBench74.2%†–
LiveBench BrowserLiveBench89.8%†–
LiveBench Agentic CodingLiveBench66.1%–
Terminal-Bench 2.1 (Vals)Vals AI85.0%†–
MCP AtlasScale AI SEAL87.2%†85.4%
HiL-BenchScale AI SEAL61.5%†–
GDPval-AA v2.1, normalised scoreArtificial Analysis62.7%–
GDPval-AA v2.1Artificial Analysis–1630
τ³-Banking (AA)Artificial Analysis47.2%40.4%
ITBench SRE (AA)Artificial Analysis49.5%–
Analyst Agent (AA)Artificial Analysis57.5%51.3%
CUA-benchVals AI13.2%–
CyberBenchVals AI70.4%†72.7%
Finance Agent v2Vals AI58.9%†–
Finance Agent v2.1Vals AI–67.5%
Harvey's Legal Agent Benchmark v1.1Vals AI–21.7%
Harvey's Legal Agent Benchmark v1Vals AI6.7%†–
Legal Research BenchVals AI55.3%†46.6%
Robo-benchVals AI5.8%–
SkillsBenchVals AI61.5%†–
SREBenchVals AI22.9%†1.9%
Tax Agent BenchVals AI50.8%†38.9%
Terminal-Bench 4.0 (Vals)Vals AI58.1%†12.6%
Terminal-Bench ScienceVals AI40.0%†2.9%
Time Horizon Index: KSPVals AI63.3%†–
Arena SearchArena (LMArena)1227†–
PostTrainBenchEpoch AI Benchmarking Hub44.6%–
Vending-Bench 2Andon Labs5421.6†–
AutomationBenchArtificial Analysis59.4%45.6%
GDP.pdf (AA)Artificial Analysis26.2%25.2%
Harvey LAB-AA v1.1Harvey6.4%–
EnterpriseOps-GymArtificial Analysis–46.8%
AA-Briefcase v1.1Artificial Analysis16691527
GDPxGDPx by SemiAnalysis8.5%–
Design Arena AgenticDesign Arena1327†1374
Terminal-Bench-Science 0.1 (AA)Artificial Analysis43.3%5.7%
CWE-Bench (AA)Artificial Analysis50.8%–
DeepSec-Bench (AA)Artificial Analysis23.5%–
CyberGym end-to-end (AA)Artificial Analysis0.8%–
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub90.2%–
FrontierMath Tier 4Epoch AI Benchmarking Hub87.8%–
OTIS Mock AIMEEpoch AI Benchmarking Hub100.0%–
ProofBenchVals AI100.0%–
LiveBench MathematicsLiveBench97.0%–
Arena MathsArena (LMArena)1526–
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub70.8%–
LiveBench 2.0 Data AnalysisLiveBench80.3%†–
LiveBench ResearchLiveBench88.5%†–
LiveBench 1.0 Data AnalysisLiveBench80.3%–
AA-Omniscience v1.1Artificial Analysis46.316.1
MMLU-ProVals AI92.4%†–
LegalBenchVals AI88.5%†–
TaxEvalVals AI76.0%†–
PRBench FinanceScale AI SEAL50.8%†–
PRBench LegalScale AI SEAL51.6%†–
BioMysteryBenchVals AI–70.0%
Excel Modeling BenchmarkVals AI76.7%†–
Excel Modeling Benchmark v1.1Vals AI76.7%†69.5%
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 v1.1: accuracyArtificial Analysis68.4%33.8%
AA-Omniscience v1.1: non-hallucinationArtificial Analysis30.0%73.3%
HealthBench Professional (AA)OpenAI57.8%–
Instruction following
LiveBench LanguageLiveBench89.5%–
LiveBench Instruction FollowingLiveBench73.0%–
Arena Instruction FollowingArena (LMArena)15011410
Human preference
Arena TextArena (LMArena)15021412
Arena Creative WritingArena (LMArena)14901345
Arena Multi-turnArena (LMArena)14851415
Arena Longer QueriesArena (LMArena)15101410
Multimodal
Arena VisionArena (LMArena)1322–
LiveBench DesignLiveBench81.6%†–
MMMU-ProArtificial Analysis–81.6%
MMMU-Pro (Vals)Vals AI90.6%†–
MortgageTaxVals AI70.8%†–
SAGEVals AI–88.6%
GeoBenchGeoBench84.0%†–
Blueprint-Bench 2Epoch AI Benchmarking Hub41.9%†–
Code2Video-AAArtificial Analysis13251020
AA-3DArtificial Analysis11391027
Long context
AA-LCR v1.1Artificial Analysis85.3%83.3%
Arena DocumentArena (LMArena)1498–
MLCRArtificial Analysis15.6%20.6%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub167.0†–
LiveBench 2.0LiveBench84.0%†–
LiveBench 1.0LiveBench83.4%–
AA Intelligence Index v5.0Artificial Analysis49.230.6
AA Intelligence Index v4.3.2Artificial Analysis53.4–
AA Progress Index v1Artificial Analysis340.8–
Vals IndexVals AI–56.1
Vals Finance IndexVals AI–61.5%
Vals RSI IndexVals AI36.1%–
Vals Science IndexVals AI–32.7%
AA Cyber IndexArtificial Analysis25.0–
Safety & honesty
FORTRESSScale AI SEAL13.7%†16.2%
Metadata
AA Openness IndexArtificial Analysis–38.9

Data as of 2026-11-13. Best configuration of each model; every score links to its source on the model pages.

DuelLab GameBench 2, release gb2-20261110-2acac640a228 (https://benchmarks.duellab.org/releases/gb2-20261110-2acac640a228/), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Scores mapped to BenchLeader model names; not endorsed by DuelLab.

What changed

  • Inkling 2 Small: BenchLeader Index 58.4 → 57.9.
  • Inkling 2 Small: 2 new results (FORTRESS, Design Arena Agentic).
  • Claude Fable 5.1 (max): BenchLeader Index 67.1 → 66.6.
  • Claude Fable 5.1 (max): 1 new result (PostTrainBench); 1 score revision.
  • Inkling 2 Small: 2 new results (MysteryMechanism, Vals Science Index); 1 score revision.
  • Claude Fable 5.1 (max): 1 new result (MirrorCode).
  • Inkling 2 Small: 3 new results (SciCode, APEX-Agents, MLCR).
  • Claude Fable 5.1 (max): 1 score revision.
  • Inkling 2 Small: 8 new results (Arena Text, Arena Hard Prompts, Arena Coding…); 2 score revisions.
  • Inkling 2 Small: BenchLeader Index 57.5 → 58.4.

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

Claude Fable 5.1 vs Inkling 2 Small: questions

Is Claude Fable 5.1 better than Inkling 2 Small?
Claude Fable 5.1 (max) leads on quality: 66.6 vs 57.9. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 (max) is ahead overall as of 13 Nov 2026, but check the category scores for your use.
Claude Fable 5.1 vs Inkling 2 Small: which is cheaper, and will that change?
Inkling 2 Small is cheaper today: $0.475 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 or Inkling 2 Small better for coding?
Claude Fable 5.1 scores higher in coding (71 vs 60 on the category index, where 50 is average). On Arena WebDev, the top shared coding benchmark, it is 1742 for Claude Fable 5.1 against 1647 for Inkling 2 Small.
Which is faster, Claude Fable 5.1 or Inkling 2 Small?
Inkling 2 Small streams ~1.5× faster (90 vs 88 output tokens per second, Artificial Analysis 7-day median).
Is Claude Fable 5.1 or Inkling 2 Small better for agents and tool use?
They are level in agentic tasks (60 vs 61 on the category index). On τ³-Banking (AA), the top shared agents & tools benchmark, it is 47.2% for Claude Fable 5.1 against 40.4% for Inkling 2 Small.
More questions (4)
Which is better for long documents?
Claude Fable 5.1 scores higher on long-context benchmarks (67 vs 66). Both take about 1M tokens: Claude Fable 5.1 1,000,000, Inkling 2 Small 1,048,576.
Which has lower latency?
Inkling 2 Small answers first: 63.9 s against 162.2 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.
Do independent benchmarks agree on Claude Fable 5.1 vs Inkling 2 Small?
Across the 28 benchmarks both have, Claude Fable 5.1 leads 26, Inkling 2 Small leads 2. Every overall index that rates both puts Claude Fable 5.1 ahead.
When was Inkling 2 Small released?
Inkling 2 Small was released on 5 Nov 2026.