Anthropicproprietary
Released: 2026-08-31

Claude Fable 5.1

Anthropic flagship hybrid reasoning foundation model delivering industry-top performance on agentic workflows and long codebase migrations.

Intelligence Index
94.8/ 100
Calibrated multi-domain composite
Throughput Speed
54tok/sec
Output streaming throughput
Time To First Token
480ms
Initial chunk server latency
LiveBench Contam-Free
84.7%
September 2026 suite score

LiveBench Multi-Domain Evaluation Breakdown

Monthly refreshed contamination-free test sets
Logical Reasoning89.7%
Coding & Repo Repair86.4%
Mathematics (AIME)88.5%
Data Analysis & Tables82.1%
Language & Comprehension80.2%
Instruction Following81.3%

Sourced Benchmark Evaluations (61)

Verified performance across authoritative benchmarks with provenance tracking.
BenchmarkStatusScoreTrustDateSource TypeProvenance
ARC-AGI-2Nearing Saturation70%
75
2026-09-12independentSource ↗
ARC-AGI-3Active58.3%
93
2026-09-12independentSource ↗
FrontierMathActive26%
98
2026-09-09independentSource ↗
PutnamBenchActive48.4%
90
2026-09-08independentSource ↗
SWE-LancerDeprecated62.2%
20
2026-09-06independentSource ↗
Omni-MATHDeprecated68.8%
10
2026-09-06independentSource ↗
SoohakActive70.7%
98
2026-09-04independentSource ↗
FrontierCodeActive53.1%
98
2026-09-04independentSource ↗
Humanity's Last ExamActive39.5%
93
2026-09-02independentSource ↗
StructFlowBenchNearing Saturation69.1%
75
2026-09-02independentSource ↗
AIMENearing Saturation88.4%
75
2026-09-02independentSource ↗
OlympiadBenchActive76.3%
80
2026-09-01independentSource ↗
MathArenaActive74.4%
99
2026-08-31independentSource ↗
FireBenchActive68.3%
95
2026-08-31independentSource ↗
Terminal-BenchActive64.1%
80
2026-08-31independentSource ↗
OpenAI-MRCRActive79.6%
80
2026-08-30independentSource ↗
SimpleQAActive49.3%
90
2026-08-30independentSource ↗
CodeContestsDeprecated59.5%
10
2026-08-30independentSource ↗
ComplexBenchNearing Saturation66.7%
80
2026-08-29independentSource ↗
SWE-bench ProActive56.7%
90
2026-08-29independentSource ↗
LongBench-ProActive77.7%
80
2026-08-29independentSource ↗
ZeroSCROLLSNearing Saturation75.8%
78
2026-08-28independentSource ↗
MultiPL-EDeprecated84.2%
10
2026-08-28independentSource ↗
LiveCodeBenchSaturated75%
39
2026-08-27independentSource ↗
AgentIFNearing Saturation55.3%
80
2026-08-27independentSource ↗
MATHSaturated91.1%
25
2026-08-27independentSource ↗
InfiniteBenchNearing Saturation80.6%
65
2026-08-27independentSource ↗
MercuryDeprecated80.5%
10
2026-08-26independentSource ↗
SCROLLSNearing Saturation75.8%
65
2026-08-26independentSource ↗
MMLU-ProNearing Saturation87.2%
75
2026-08-26independentSource ↗
RULERNearing Saturation87.2%
84
2026-08-25independentSource ↗
TabMWPSaturated85.6%
25
2026-08-25independentSource ↗
CyberSecEvalDeprecated82.4%
10
2026-08-25independentSource ↗
SWE-bench VerifiedSaturated71.4%
25
2026-08-24independentSource ↗
MMLU-ReduxSaturated92.9%
25
2026-08-24independentSource ↗
QuALITYNearing Saturation83.4%
78
2026-08-24independentSource ↗
LongBenchNearing Saturation81.5%
65
2026-08-23independentSource ↗
SWE-benchDeprecated62.2%
10
2026-08-23independentSource ↗
MGSMNearing Saturation88.4%
65
2026-08-23independentSource ↗
AGIEvalSaturated77.1%
25
2026-08-22independentSource ↗
QASPERNearing Saturation78.7%
65
2026-08-22independentSource ↗
TruthfulQASaturated83.4%
25
2026-08-22independentSource ↗
GSM-HardDeprecated89.3%
10
2026-08-21independentSource ↗
SuperGLUESaturated91.5%
25
2026-08-21independentSource ↗
CodeXGLUEDeprecated86%
23
2026-08-20independentSource ↗
MT-BenchNearing Saturation8.4%
75
2026-08-20independentSource ↗
BIG-Bench HardSaturated87.9%
25
2026-08-20independentSource ↗
WinoGrandeSaturated93.3%
28
2026-08-19independentSource ↗
MBPP+Nearing Saturation93.3%
65
2026-08-19independentSource ↗
IFEvalDeprecated79.7%
25
2026-08-19independentSource ↗
GPQANearing Saturation83.4%
78
2026-08-19independentSource ↗
Needle-in-a-HaystackSaturated99%
44
2026-08-18independentSource ↗
HumanEval+Saturated98.8%
25
2026-08-18independentSource ↗
CommonsenseQASaturated94.2%
28
2026-08-18independentSource ↗
MBPPSaturated97%
25
2026-08-17independentSource ↗
GSM8KSaturated100%
25
2026-08-17independentSource ↗
GLUESaturated96.9%
28
2026-08-17independentSource ↗
MMLUSaturated96.7%
25
2026-08-16independentSource ↗
HumanEvalSaturated100%
25
2026-08-16independentSource ↗
ARC-AGISaturated84.3%
25
2026-08-16independentSource ↗
LiveBench (Continuous)Active84.7%
94
2025-02-01independentSource ↗
Anthropic Python SDKAPI Ready
import anthropic

client = anthropic.Anthropic()
message = client.messages.create(
    model="claude-fable-5-1",
    max_tokens=2048,
    temperature=0,
    messages=[{"role": "user", "content": "Execute SWE-bench verified repository fix"}]
)
print(message.content[0].text)

Evaluation & Sourcing Notes

Scores listed for Claude Fable 5.1 represent verified evaluations extracted from official research papers, independent evaluation suites (HELM, LMSYS, OpenCompass, LiveBench), and verified audit reports.

All benchmarks marked as saturated or deprecated reflect historical performance where the benchmark no longer provides active discriminative power.