Head-to-head comparison

Claude Fable 5.1 vs. Claude Sonnet 4.6

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series: 160
distinct benchmarks: 19
latest retrieval: 2026-10-15

First modelSecond model

Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for Claude Fable 5.1 and Claude Sonnet 4.6
Attribute	Claude Fable 5.1	Claude Sonnet 4.6
Provider	Anthropic	Anthropic
Released	Sep 1, 2026	Feb 2026
Availability	Active	Active
Model type	Proprietary	Proprietary
Parameters	Not published	Not published
Architecture	Not published	Not published
Context window	1,000,000 tokens	1,000,000 tokens
Knowledge cutoff	June 2026	August 2025
Technical sources	Model	Model, Context

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for Claude Fable 5.1 and Claude Sonnet 4.6
Price type	Claude Fable 5.1	Claude Sonnet 4.6
API input	$10	$3
API output	$50	$15
Cache read	$0.25	$0.3
Cache write (5 min.)	$12.5	$3.75
Cache write (1 hr.)	$20	$6
Price verified	09/22/2026 Source	09/22/2026 Source

Claude Fable 5.1Claude Sonnet 4.6

API inputUSD per 1M tokens, base tier

Claude Fable 5.1$10

Claude Sonnet 4.6$3

API outputUSD per 1M tokens, base tier

Claude Fable 5.1$50

Claude Sonnet 4.6$15

Cache readUSD per 1M tokens, base tier

Claude Fable 5.1$0.25

Claude Sonnet 4.6$0.3

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for Claude Fable 5.1 and Claude Sonnet 4.6
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
Claude Fable 5.1	Anthropic	Direct from developerStandard API	Lowest listed price: $10	Lowest listed price: $50	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock	Lowest listed price: $10	Lowest listed price: $50	Source10/17/2026
	Anthropic	Via OpenRouteranthropic	Lowest listed price: $10	Lowest listed price: $50	Source10/17/2026
	Azure	Via OpenRouterazure	Lowest listed price: $10	Lowest listed price: $50	Source10/17/2026
	Google	Via OpenRoutergoogle-vertex/global	Lowest listed price: $10	Lowest listed price: $50	Source10/17/2026
Claude Sonnet 4.6	Anthropic	Direct from developerStandard API	Lowest listed price: $3	Lowest listed price: $15	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/eu-west-1	$3.3	$16.5	Source10/17/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/global	Lowest listed price: $3	Lowest listed price: $15	Source10/17/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us	$3.3	$16.5	Source10/17/2026
	Anthropic	Via OpenRouteranthropic	Lowest listed price: $3	Lowest listed price: $15	Source10/17/2026
	Azure	Via OpenRouterazure/global	Lowest listed price: $3	Lowest listed price: $15	Source10/17/2026
	Claude Platform on AWS	Via OpenRouterclaude-on-aws	Lowest listed price: $3	Lowest listed price: $15	Source10/17/2026
	Google	Via OpenRoutergoogle-vertex/europe	$3.3	$16.5	Source10/17/2026
	Google	Via OpenRoutergoogle-vertex/global	Lowest listed price: $3	Lowest listed price: $15	Source10/17/2026
	Google	Via OpenRoutergoogle-vertex/us-east5	$3.3	$16.5	Source10/17/2026

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

Not enough directly matched categories for a reliable radar

Only 0 of at least 5 categories have comparable, direct model measurements. The benchmark tables below show the available evidence without filling missing axes.

Claude Fable 5.1Claude Sonnet 4.6

Code MigrationOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.154.607 %

Claude Sonnet 4.639.892 %

EMBOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.176.67 %

Claude Sonnet 4.660.154 %

Finance Agent (v2)Overall. Higher is better. Test setup not documented as identical

Claude Fable 5.158.877 %

Claude Sonnet 4.651.035 %

GPQA DiamondOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.193.434 %

Claude Sonnet 4.685.606 %

Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. Test setup not documented as identical

Claude Fable 5.16.667 %

Claude Sonnet 4.65 %

Legal Research BenchOverall · All-pass. Higher is better. Test setup not documented as identical

Claude Fable 5.155.288 %

Claude Sonnet 4.638.462 %

LegalBenchOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.188.511 %

Claude Sonnet 4.682.12 %

LiveCodeBench v6Overall. Higher is better. Test setup not documented as identical

Claude Fable 5.190.515 %

Claude Sonnet 4.682.091 %

MMLU-ProOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.192.375 %

Claude Sonnet 4.687.341 %

MMMU-ProOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.190.636 %

Claude Sonnet 4.683.584 %

MortgageTaxOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.170.786 %

Claude Sonnet 4.667.726 %

ProgramBenchOverall. Higher is better. Test setup not documented as identical

Claude Fable 5.17 %

Claude Sonnet 4.60.5 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Fable 5.1 and Claude Sonnet 4.6
Benchmark and task	Claude Fable 5.1	Claude Sonnet 4.6	Source
Code MigrationOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value54.607 %	39.892 %	Vals AI Source details Data as of: 10/12/2026
EMBOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value76.67 %	60.154 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Overall Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value58.877 %	51.035 %	Vals AI Source details Data as of: 10/12/2026
GPQA DiamondOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value93.434 %	85.606 %	Vals AI Source details Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value6.667 %	5 %	Vals AI Source details Data as of: 10/12/2026
Legal Research BenchOverall · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value55.288 %	38.462 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value88.511 %	82.12 %	Vals AI Source details Data as of: 10/13/2026
LiveCodeBench v6Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value90.515 %	82.091 %	Vals AI Source details Data as of: 09/01/2026
MMLU-ProOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value92.375 %	87.341 %	Vals AI Source details Data as of: 09/01/2026
MMMU-ProOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value90.636 %	83.584 %	Vals AI Source details Data as of: 09/01/2026
MortgageTaxOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value70.786 %	67.726 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully resolved rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value7 %	0.5 %	Vals AI Source details Data as of: 10/12/2026
Public Benefits Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value74.899 %	62.449 %	Vals AI Source details Data as of: 10/12/2026
SAGEOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 30,000 tokens	Higher measured value48.526 %	46.582 %	Vals AI Source details Data as of: 10/08/2026
SkillsBenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens	Higher measured value61.552 %	49.052 %	Vals AI Source details Data as of: 09/27/2026
Tax Agent BenchOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value49.194 %	25.84 %	Vals AI Source details Data as of: 10/12/2026
TaxEval v2Overall Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	75.961 %	Higher measured value77.106 %	Vals AI Source details Data as of: 09/01/2026
Terminal-Bench 2.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterClaude Fable 5.1: Compute: high, Temperature: 1, Output limit: 128,000 tokens Claude Sonnet 4.6: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value85.019 %	57.303 %	Vals AI Source details Data as of: 09/28/2026
Vibe Code Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens	Higher measured value90.263 %	51.476 %	Vals AI Source details Data as of: 10/12/2026
Code MigrationCLI Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value52.809 %	30.333 %	Vals AI Source details Data as of: 10/12/2026
EMBComps Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value82.233 %	61.52 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Adjustments Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value54.393 %	48.92 %	Vals AI Source details Data as of: 10/12/2026
GPQA DiamondFew-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value92.929 %	85.859 %	Vals AI Source details Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value89.855 %	87.319 %	Vals AI Source details Data as of: 10/12/2026
Legal Research BenchAdministrative / Regulatory · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value68.182 %	43.939 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchConclusion Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value92.511 %	87.991 %	Vals AI Source details Data as of: 10/13/2026
LiveCodeBench v6Easy Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value99.068 %	98.758 %	Vals AI Source details Data as of: 09/01/2026
MMLU-ProBiology Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value96.095 %	92.748 %	Vals AI Source details Data as of: 09/01/2026
MortgageTaxNumerical Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value77.583 %	74.96 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchAlmost Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: almost-resolved rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value53.5 %	2 %	Vals AI Source details Data as of: 10/12/2026
SAGEAutomata Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 30,000 tokens	34.524 %	Higher measured value35.318 %	Vals AI Source details Data as of: 10/08/2026
SkillsBenchNo Skills Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens	Higher measured value44.828 %	27.827 %	Vals AI Source details Data as of: 09/27/2026
Tax Agent BenchControversy & Precedence Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value26.667 %	10 %	Vals AI Source details Data as of: 10/12/2026
TaxEval v2Correctness Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	64.105 %	Higher measured value65.822 %	Vals AI Source details Data as of: 09/01/2026
Terminal-Bench 2.1Easy Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterClaude Fable 5.1: Compute: high, Temperature: 1, Output limit: 128,000 tokens Claude Sonnet 4.6: Compute: max, Temperature: 1, Output limit: 128,000 tokens	No direct winner100 %	No direct winner100 %	Vals AI Source details Data as of: 09/28/2026
Code MigrationCOBOL Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	60 %	Higher measured value68.571 %	Vals AI Source details Data as of: 10/12/2026
EMBDataroom Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value86.736 %	78.493 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)All-Pass Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value47.773 %	38.795 %	Vals AI Source details Data as of: 10/12/2026
GPQA DiamondZero-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value93.939 %	85.354 %	Vals AI Source details Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	No direct winner0 %	No direct winner0 %	Vals AI Source details Data as of: 10/12/2026
Legal Research BenchAdministrative / Regulatory · Weighted partial credit Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: weighted partial-credit scoreScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value92.519 %	86.797 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchInterpretation Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value86.902 %	82.469 %	Vals AI Source details Data as of: 10/13/2026
LiveCodeBench v6Hard Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value80.571 %	60.571 %	Vals AI Source details Data as of: 09/01/2026
MMLU-ProBusiness Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value95.184 %	91.888 %	Vals AI Source details Data as of: 09/01/2026
MortgageTaxSemantic Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value63.99 %	60.493 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchFully Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: fully resolved rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value7 %	0.5 %	Vals AI Source details Data as of: 10/12/2026
SAGECalculus Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterClaude Fable 5.1: Compute: max, Temperature: 1, Output limit: 30,000 tokens Claude Sonnet 4.6: Temperature: 1, Output limit: 30,000 tokens	Higher measured value83.642 %	60.494 %	Vals AI Source details Data as of: 10/08/2026
SkillsBenchWith Skills Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens	Higher measured value61.552 %	49.052 %	Vals AI Source details Data as of: 09/27/2026
Tax Agent BenchControversy & Precedence Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value70.553 %	57.949 %	Vals AI Source details Data as of: 10/12/2026
TaxEval v2Stepwise Reasoning Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	87.817 %	Higher measured value88.389 %	Vals AI Source details Data as of: 09/01/2026
Terminal-Bench 2.1Hard Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterClaude Fable 5.1: Compute: high, Temperature: 1, Output limit: 128,000 tokens Claude Sonnet 4.6: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value82.222 %	34.444 %	Vals AI Source details Data as of: 09/28/2026
Code MigrationCode Quality Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: mean reviewer code-quality ratingScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value4.513 / 5	3.997 / 5	Vals AI Source details Data as of: 10/12/2026
EMBDCF Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value69.88 %	38.28 %	Vals AI Source details Data as of: 10/12/2026
Finance Agent (v2)Comparables Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value45.982 %	41.003 %	Vals AI Source details Data as of: 10/12/2026
Harvey's Legal Agent BenchmarkArbitration International Dispute Resolution · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value89.606 %	85.663 %	Vals AI Source details Data as of: 10/12/2026
Legal Research BenchBusiness & Commercial · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value62.791 %	34.884 %	Vals AI Source details Data as of: 10/12/2026
LegalBenchIssue Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value92.72 %	86.574 %	Vals AI Source details Data as of: 10/13/2026
LiveCodeBench v6Medium Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value91.906 %	86.945 %	Vals AI Source details Data as of: 09/01/2026
MMLU-ProChemistry Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value93.816 %	91.873 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchRaw Pass Rate Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: raw test pass rateScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value82.688 %	59.103 %	Vals AI Source details Data as of: 10/12/2026
SAGELinear Algebra Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 30,000 tokens	Higher measured value71.371 %	63.158 %	Vals AI Source details Data as of: 10/08/2026
Tax Agent BenchCurrent & Temporal Analysis Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value59.816 %	33.151 %	Vals AI Source details Data as of: 10/12/2026
Terminal-Bench 2.1Medium Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterClaude Fable 5.1: Compute: high, Temperature: 1, Output limit: 128,000 tokens Claude Sonnet 4.6: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value85.455 %	66.667 %	Vals AI Source details Data as of: 09/28/2026
EMBLBO Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterSettings: Compute: max, Temperature: 1, Output limit: 128,000 tokens	Higher measured value69.64 %	52.536 %	Vals AI Source details Data as of: 10/12/2026
Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Our tests

SVG short test

One SVG prompt and fixed output settings. Captures are shown only with 0 reported reasoning tokens or documented lack of reasoning controls. Identical test conditions do not make the models' internal compute identical.

Shared test round: 4ae5d8eeb9a9

Claude Fable 5.1

Unavailable in this round

Claude Sonnet 4.6

Earlier tests

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Fable 5.1

Reasoning (requested): high

Current attempt

Run date: Sep 7, 2026
API provider: openrouter
Requested API model: anthropic/claude-fable-5.1
API model reported in response: anthropic/claude-fable-5.1
Reasoning setting: high
Pinned endpoint: Anthropic | anthropic/claude-fable-5.1-20260831
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating
Response time: 27 s

Visually reviewed. This individual test does not establish overall model quality.

Claude Sonnet 4.6

The response reached the token limit. No complete recording is available.

Reasoning (requested): high

Current attempt

Run date: Oct 6, 2026
API provider: openrouter
Requested API model: anthropic/claude-sonnet-4.6
API model reported in response: anthropic/claude-sonnet-4.6
Reasoning setting: high
Pinned endpoint: Anthropic | anthropic/claude-4.6-sonnet-20260217
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Failed
Response time: 106 s

Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.

Earlier attempts (2)

Oct 2, 2026API request failedReasoning setting: high
Oct 1, 2026API request failedReasoning setting: high

Prompt and test conditions

Generate an SVG of a pelican riding a bicycle

Token limit including reasoning: 8,192 tokens

Task origin (Simon Willison)

How to read this comparison

Winning one benchmark is not an overall verdict

Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

More matchups

Compare Claude Fable 5.1 and Claude Sonnet 4.6 with other leading models using the same data and benchmark logic.

View the complete LLM comparison

Claude Fable 5.1 vs. Claude Sonnet 4.6

Change model selection

General specifications

API pricing compared

Shared benchmarks

Capability profile from matched benchmarks

Our tests

SVG short test

Claude Fable 5.1

Claude Sonnet 4.6

Pelican on a bicycle

Winning one benchmark is not an overall verdict

Related LLM comparisons