BenchLeader

Claude Fable 5.1

Reasoning effort

Claude Fable 5.1 is an Anthropic proprietary reasoning model, released 1 Sept 2026. Its best configuration (max reasoning effort) ranks #5 of 775 on the BenchLeader Index at 70.6 ±4.6, in the top ten. The ± is the point: 44 other configurations score within that range, so they and this one cannot be told apart on quality alone — price and speed are what separate them. It scores highest in composite (89) and lowest in agents & tools (61). At $20.00 per million tokens blended it is among the most expensive ranked models. Output speed of 69 tokens per second puts it slower than most, with a first answer in 221.4 s. It has been measured at 6 reasoning-effort settings; this summary describes the best-scoring one, and the tabs above switch between them. Last measured 19 Oct 2026.

Blended price
$20.00/M
$10.00 in · $50.00 out
Output speed
69 tok/s
measured by Artificial Analysis
First answer
221 s
first token 3.52 s
Context
1M
Full answer
229 s
median, reasoning included
Cost per run
$7.63
one full Intelligence Index run
Released
1 Sept 2026
How it scores by categoryDashed line = average model (50). One step of 15 = one standard deviation.
  1. Overall index71
  2. Reasoning77
  3. Coding75
  4. Agents & tools61
  5. Maths73
  6. Knowledge78
  7. Human preference70
  8. Multimodal67
  9. Long context68
  10. Composite89

Versions

Anthropic has shipped 2 models under this name. Each is ranked on its own results; a newer version often has fewer results so far, which holds its index nearer the average until more arrive.

ModelReleasedIndexRank
Claude Fable 5.1maxthis page1 Sept 202670.6#5
Claude Fable 5max9 Jun 202669.4#11

Reasoning-effort configurations

The same model behaves differently depending on how much it is allowed to think. Each row is one setting, scored only on the benchmarks that were run at that setting. “Not stated” collects results from publishers that did not say which setting they used; for a reasoning model that is usually its thinking mode, but we do not assume it. Pick a setting here or at the top of the page to see its price, speed and category scores.

EffortIndexRankSpeedFirst answerChat reply costCategories
low65.1#4057 tok/s1.99 s$0.019Agents & tools 59 · Coding 62 · Composite 82 · Knowledge 77 · Long context 66 · Reasoning 74
medium67.3#2556 tok/s4.35 s$0.019Agents & tools 64 · Coding 63 · Composite 84 · Knowledge 78 · Long context 68 · Reasoning 77
high69.4#1358 tok/s21 s$0.019Agents & tools 65 · Coding 72 · Composite 87 · Knowledge 80 · Long context 67 · Reasoning 78
xhigh69.5#1064 tok/s83 s$0.019Agents & tools 68 · Coding 69 · Composite 89 · Knowledge 81 · Long context 67 · Reasoning 79
maxbest70.6#569 tok/s221 s$0.019Agents & tools 61 · Coding 75 · Composite 89 · Human preference 70 · Knowledge 78 · Long context 68 · Maths 73 · Multimodal 67 · Reasoning 77
not stated66.2#3360 tok/s3.52 s$0.019Agents & tools 69 · Coding 73 · Composite 73 · Knowledge 65

What more thinking costs

Turning the effort up buys index points and multiplies the bill. Here max costs 3.2× low for +5.5 on the index — 3.3 points per doubling of spend. Compare that with other models.

low $2.37max $7.63

How its index has moved

8 Sept 2026 to 20 Oct 2026
606877
  • max
  • xhigh
  • high
  • medium

The index is recomputed from scratch every day, so a line moves when a new benchmark result lands, when a publisher revises a score, or when the models it is normalised against change. Early movement usually means the score is still settling.

Benchmark results

See all LLM benchmarks. One column per reasoning effort. Rank is among every configuration of every model on that benchmark. Hover a score for the run it came from.

Reasoning

Benchmarklowmediumhighxhighmaxnot statedSourceTrend
Humanity's Last Exam–––46.5%#2––Scale AI / CAIS
Arena Hard Prompts––––1521#8–Arena (LMArena)
LiveBench 2.0 Reasoningnot in indexeffort not stated–––––91.7%#5LiveBench
LiveBench 1.0 Reasoningnot in index––––91.7%#4–LiveBench
GPQA Diamond (AA)not in index88.1%#9188.6%#8790.6%#5893.4%#2193.7%#11–Artificial Analysis
Humanity's Last Exam (AA)not in index48.9%#3053.8%#1555.9%#658.7%#359.1%#2–Artificial Analysis
GPQA Diamond (Vals)not in indexeffort not stated–––––93.4%#7Vals AI
ARC-AGI-190.0%#7494.5%#3796.0%#2996.5%#2397.5%#12–ARC Prize
ARC-AGI-278.3%#4086.3%#2788.8%#2090.0%#1490.0%#14–ARC Prize
CritPt27.7%#2929.1%#2030.3%#1531.1%#1029.7%#19–Artificial Analysis
MysteryMechanismnot in indexeffort not stated–––––47.8%#4Vals AI
Chess Puzzlesnot in index––––48.0%#19–Epoch AI Benchmarking Hub
Mystery Game Puzzlesnot in index––––58.0%#7–Epoch AI Benchmarking Hub
LMCAnot in index63.5%#2165.3%#1065.1%#1165.1%#12–65.5%#8Epoch AI Benchmarking Hub
DTBenchnot in index94.1%#5897.1%#1796.5%#2297.6%#5–97.6%#5Epoch AI Benchmarking Hub

Coding

Benchmarklowmediumhighxhighmaxnot statedSourceTrend
SciCode55.7%#4555.3%#4957.6%#2660.9%#763.1%#3–SciCode
WeirdML––92.3%#5–92.9%#3–WeirdML
FrontierCode–50.9%#6––––Cognition
GSO-Bencheffort not stated–––––88.2%#1GSO-Bench
Arena Coding––––1537#14–Arena (LMArena)
Arena WebDev––––1743#5–Arena (LMArena)
LiveBench 2.0 Codingnot in indexeffort not stated–––––97.7%#2LiveBench
LiveBench 1.0 Codingnot in index––––86.4%#5–LiveBench
SciCode (AA)not in index56.7%#3456.4%#3858.7%#2060.9%#863.1%#3–Artificial Analysis
LiveCodeBencheffort not stated–––––90.5%#1Vals AI
IOIeffort not stated–––––90.8%#6Vals AI
Code Migrationnot in indexeffort not stated–––––54.6%#11Vals AI
ProgramBenchnot in indexeffort not stated–––––7.0%#2Vals AI
Vibe Code Bench 1-100not in indexeffort not stated–––––28.0%#4Vals AI
Vibe Code Bench v1.1not in indexeffort not stated–––––90.3%#6Vals AI
SWE Atlas: Codebase QnAnot in index–––60.0%#2––Scale AI SEAL
SWE Atlas: Refactoringnot in index–––56.7%#2––Scale AI SEAL
SWE Atlas: Test Writingnot in index–––67.0%#1––Scale AI SEAL
MirrorCodenot in index––73.3%#2–––Epoch AI Benchmarking Hub
CursorBenchnot in index45.1%#2446.8%#1849.2%#1351.6%#1051.8%#9–Cursor
ALE-Benchnot in index––2143.2#7–––Epoch AI Benchmarking Hub
FrontierSWEnot in index––––56.3%#4–Epoch AI Benchmarking Hub
Terminal-Bench 4.0 (AA)not in index40.4%#3045.0%#2452.0%#1555.0%#1152.0%#15–Artificial Analysis
Terminal-Bench 2.1 (AA)not in index85.0%#2688.0%#1289.9%#391.0%#291.4%#1–Artificial Analysis
Startrise Frontendnot in indexeffort not stated–––––77.1%#6Startrise
FrontierCode 1.1 (AA)not in index––––49.0%#6–Artificial Analysis

Agents & tools

Benchmarklowmediumhighxhighmaxnot statedSourceTrend
Terminal-Bench43.3%#4453.9%#2754.5%#2557.9%#1957.9%#19–Terminal-Bench
Remote Labor Indexeffort not stated–––––17.9%#3Scale AI / CAIS
APEX-Agents––59.7%#13––68.6%#4Mercor
Arena Agent––––14.3#3–Arena (LMArena)
LiveBench Long Agenticnot in indexeffort not stated–––––80.8%#3LiveBench
LiveBench Browsernot in indexeffort not stated–––––100.0%#1LiveBench
LiveBench Agentic Codingnot in index––––66.1%#3–LiveBench
Terminal-Bench 2.1 (Vals)effort not stated–––––85.0%#4Vals AI
MCP Atlaseffort not stated–––––87.2%#2Scale AI SEAL
HiL-Bencheffort not stated–––––61.5%#6Scale AI SEAL
GDPval-AA v2.1not in index48.4%#5552.3%#4456.7%#2161.6%#862.7%#6–Artificial Analysis
τ³-Banking (AA)39.0%#3441.0%#2743.1%#2145.8%#1247.2%#8–Artificial Analysis
ITBench SRE (AA)not in index––––49.5%#6–Artificial Analysis
Analyst Agent (AA)not in index––––57.5%#2–Artificial Analysis
CUA-benchnot in index––––13.2%#3–Vals AI
CyberBenchnot in indexeffort not stated–––––70.4%#21Vals AI
Finance Agent v2not in indexeffort not stated–––––58.9%#9Vals AI
Legal Research Benchnot in indexeffort not stated–––––55.3%#1Vals AI
SkillsBenchnot in indexeffort not stated–––––61.5%#6Vals AI
SREBenchnot in indexeffort not stated–––––22.9%#9Vals AI
Tax Agent Benchnot in indexeffort not stated–––––49.2%#1Vals AI
Terminal-Bench 4.0 (Vals)not in indexeffort not stated–––––58.1%#4Vals AI
Terminal-Bench Sciencenot in indexeffort not stated–––––40.0%#6Vals AI
Time Horizon Index: KSPnot in indexeffort not stated–––––63.3%#3Vals AI
Arena Searchnot in index––1233#4–––Arena (LMArena)
Vending-Bench 2not in indexeffort not stated–––––5421.6#27Andon Labs
AutomationBenchnot in index52.2%#7154.7%#5955.3%#5557.8%#4759.4%#40–Artificial Analysis
GDP.pdf (AA)not in index28.0%#1326.8%#1826.8%#1826.2%#2226.2%#22–Artificial Analysis
Harvey LAB-AA v1.1not in index––––6.4%#7–Harvey
AA-Briefcase v1.1not in index–––1655#101672#7–Artificial Analysis
Terminal-Bench-Science 0.1 (AA)not in index––––43.3%#9–Artificial Analysis
CWE-Bench (AA)––––50.8%#13–Artificial Analysis
DeepSec-Bench (AA)––––23.5%#10–Artificial Analysis
CyberGym end-to-end (AA)––––0.8%#14–Artificial Analysis

Knowledge

Benchmarklowmediumhighxhighmaxnot statedSourceTrend
SimpleQA Verified––––70.8%#6–Epoch AI Benchmarking Hub
LiveBench 2.0 Data Analysisnot in indexeffort not stated–––––80.3%#8LiveBench
LiveBench Researchnot in indexeffort not stated–––––82.0%#14LiveBench
LiveBench 1.0 Data Analysisnot in index––––80.3%#9–LiveBench
AA-Omniscience34.1#2437.6#2140.8#1442.4#843.5#3–Artificial Analysis
MMLU-Proeffort not stated–––––92.4%#1Vals AI
LegalBencheffort not stated–––––88.5%#2Vals AI
TaxEvaleffort not stated–––––76.0%#8Vals AI
PRBench Financeeffort not stated–––––50.8%#9Scale AI SEAL
PRBench Legaleffort not stated–––––51.6%#8Scale AI SEAL
Excel Modeling Benchmarknot in indexeffort not stated–––––76.7%#1Vals AI
MedCodenot in indexeffort not stated–––––53.5%#8Vals AI
MedScribenot in indexeffort not stated–––––91.3%#2Vals AI
Public Benefits Benchnot in indexeffort not stated–––––74.9%#2Vals AI
EBR-benchnot in index––––57.1%#4–Epoch AI Benchmarking Hub
GDP.pdfnot in index––29.6%#10–27.6%#12–Epoch AI Benchmarking Hub
AA-Omniscience: accuracynot in index60.2%#2063.1%#1064.9%#666.2%#267.2%#1–Artificial Analysis
AA-Omniscience: non-hallucinationnot in index34.4%#19030.9%#21831.2%#21529.4%#22427.4%#228–Artificial Analysis

Instruction following

BenchmarkmaxSourceTrend
LiveBench Languagenot in index89.5%#3LiveBench
LiveBench Instruction Followingnot in index73.0%#18LiveBench
Arena Instruction Followingnot in index1499#7Arena (LMArena)

Human preference

Multimodal

Benchmarkmaxnot statedSourceTrend
Arena Vision1320#4–Arena (LMArena)
LiveBench Designnot in indexeffort not stated–83.4%#4LiveBench
MMMU-Pro (Vals)not in indexeffort not stated–90.6%#1Vals AI
MortgageTaxnot in indexeffort not stated–70.8%#2Vals AI
SAGEnot in indexeffort not stated–48.5%#27Vals AI
Blueprint-Bench 2not in indexeffort not stated–41.9%#4Epoch AI Benchmarking Hub
AA-3Dnot in index1133#5–Artificial Analysis

Long context

BenchmarklowmediumhighxhighmaxSourceTrend
AA-LCR82.3%#4084.7%#583.7%#1583.0%#2585.3%#4Artificial Analysis
Arena Documentnot in index––––1493#6Arena (LMArena)
MLCRnot in index––––71.1%#2Artificial Analysis

Composite

Benchmarklowmediumhighxhighmaxnot statedSourceTrend
Epoch Capabilities Indexnot in indexeffort not stated–––––166.5#4Epoch AI Benchmarking Hub
LiveBench 2.0effort not stated–––––88.0%#1LiveBench
LiveBench 1.0not in index––––83.4%#1–LiveBench
AA Intelligence Index v4.3.246.8#2948.9#2351.1#1553.2#753.4#6–Artificial Analysis
AA Cyber Indexnot in index––––25.0#15–Artificial Analysis

Safety & honesty

Benchmarknot statedSourceTrend
FORTRESSnot in index13.7%#56Scale AI SEAL

Where it wins

Benchmarks where this configuration ranks in the top five of every configuration measured.

Where to run it

Every provider serving this model through OpenRouter, with throughput and first-token latency measured on live traffic over the last 30 minutes and each provider’s own price. Purple marks the best in each column.

ProviderSpeedFirst tokenInput $/MOutput $/MContextQuantisation
Google Vertex70 tok/s2.12 s$10.00$50.001M–
Anthropic58 tok/s3.60 s$10.00$50.001M–
Azure43 tok/s2.65 s$10.00$50.001M–
Amazon Bedrock (BYOK Only)43 tok/s6.35 s$10.00$50.001M–

What a task costs

Estimates from list price, output speed and time to first answer for the best configuration. “With caching” assumes three-quarters of the input is served from the prompt cache at $0.250 per 1M. Reasoning tokens are not modelled.

WorkloadTokens in / outCostWith cachingTime
Chat reply400 / 300$0.019$0.0163.8 min
Summarize a 30-page report12,000 / 600$0.150$0.0623.8 min
Code edit6,000 / 1,500$0.135$0.0914.1 min
Agentic coding session60,000 / 4,000$0.800$0.3614.7 min
Structured extraction2,000 / 200$0.030$0.0153.7 min

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See also

Data as of 21 Oct 2026. Compare these configurations.

Cite as: BenchLeader, “Claude Fable 5.1: benchmarks, pricing, speed and rank”, https://www.benchleader.com/models/claude-fable-5-1, data as of 21 Oct 2026.