Noometry

Model comparison

Claude 2 vs Claude Fable 5.1

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.0 on the Noometry Index.

Last verified . 3 shared benchmarks.

Claude 2 Anthropic

25.0

Rank #346 Reported

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Summary

  • They share 3 benchmarks with published results for both. Claude 2 scores higher in 0 categories and Claude Fable 5.1 in 3 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 9.3.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 2.5% for Claude 2 and 100% for Claude Fable 5.1.

Side by side

Claude 2Claude Fable 5.1
ProviderAnthropicAnthropic
Noometry Index25.069.0
Released2023-07-112026-09-01
WeightsProprietaryProprietary
Context window—1M
Max output—128K
Input $ / M tokens—$10
Output $ / M tokens—$50
Results tracked852

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Category by category

Coding Not comparable

Claude 2: —, Claude Fable 5.1: 74.7 (#1)

BenchmarkClaude 2Claude Fable 5.1
FrontierCode—50.9%
CursorBench—51.8%
LMArena WebDev—1744
FrontierSWE—56.3%
SciCode—63.1%
GSO—88.2%
WeirdML—92.9%
LMArena Coding—1528
MirrorCode—73.3%
ALE-Bench—2,143
HumanEval+61.6%—

Agentic & Tool Use Not comparable

Claude 2: —, Claude Fable 5.1: 50.7 (#5)

BenchmarkClaude 2Claude Fable 5.1
APEX-Agents—68.6%
Remote Labor Index—17.9%
GDP.pdf—29.6%
Vending-Bench 2—5,422

Reasoning Claude Fable 5.1 leads

Claude 2: 21.7 (#216), Claude Fable 5.1: 76.7 (#7)

BenchmarkClaude 2Claude Fable 5.1
DTBench51.9%97.6%
Epoch Capabilities Index120.13164.7
ARC-AGI-2—90%
NYT Connections (extended)—90%
ARC-AGI-1—97.5%
CritPt—31.1%
Chess Puzzles—47%
EBR-Bench—57.1%
LMArena Hard Prompts—1526
Mystery Game Puzzles—58%
LMCA—65.5%

Math Claude Fable 5.1 leads

Claude 2: 9.3 (#320), Claude Fable 5.1: 89.6 (#4)

BenchmarkClaude 2Claude Fable 5.1
OTIS Mock AIME 2024-20252.5%100%
FrontierMath (Tiers 1-3)—90.2%
FrontierMath Tier 4—87.8%
ProofBench—100%
LMArena Math—1525
MATH Level 511.7%—
FrontierMath Erdős—0%

Knowledge Claude Fable 5.1 leads

Claude 2: 16.9 (#287), Claude Fable 5.1: 69.6 (#6)

BenchmarkClaude 2Claude Fable 5.1
GPQA Diamond34.7%—
Humanity's Last Exam—46.5%
SimpleQA Verified—70.8%
LMArena Expert—1535
MMLU78.5%—
TriviaQA87.5%—

Multimodal Not comparable

Claude 2: —, Claude Fable 5.1: 53.9 (#4)

BenchmarkClaude 2Claude Fable 5.1
LMArena Vision—1318
Blueprint-Bench 2—41.9%
Furniture Assembly—70%
LMArena Document—1513

Multilingual Not comparable

Claude 2: —, Claude Fable 5.1: 59.1 (#3)

BenchmarkClaude 2Claude Fable 5.1
LMArena Non-English—1507
LMArena Chinese—1586
LMArena French—1525
LMArena German—1500
LMArena Japanese—1543
LMArena Korean—1534
LMArena Russian—1521
LMArena Spanish—1516

Instruction Following Not comparable

Claude 2: —, Claude Fable 5.1: 79.2 (#6)

BenchmarkClaude 2Claude Fable 5.1
LMArena Instruction Following—1517

Long Context Not comparable

Claude 2: —, Claude Fable 5.1: 46.7 (#20)

BenchmarkClaude 2Claude Fable 5.1
LMArena Longer Query—1522

Writing & Preference Not comparable

Claude 2: —, Claude Fable 5.1: 79.2 (#2)

BenchmarkClaude 2Claude Fable 5.1
LMArena Text—1510
LMArena Creative Writing—1507
EQ-Bench Creative Writing—2162
LMArena Multi-Turn—1492

Frequently asked questions

Is Claude 2 better than Claude Fable 5.1?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.0 on the Noometry Index.

How many benchmarks do Claude 2 and Claude Fable 5.1 share?

3 benchmarks have published results for both models. Claude 2 has 8 scored results on Noometry and Claude Fable 5.1 has 52.

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