Model comparison

Claude Fable 5.1 vs GPT-5.4 Pro

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 58.9 on the Noometry Index.

Last verified . 10 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

GPT-5.4 Pro OpenAI

58.9

Rank #18 Confirmed

Summary

  • They share 10 benchmarks with published results for both. Claude Fable 5.1 scores higher in 4 categories and GPT-5.4 Pro in 0 categories; 4 gaps are clear of the uncertainty.
  • The widest gap is in coding, where Claude Fable 5.1 leads 74.7 to 43.2.
  • The biggest single-benchmark swing is WeirdML: 92.9% for Claude Fable 5.1 and 57.4% for GPT-5.4 Pro.
  • Claude Fable 5.1 is cheaper at $10 / $50 per million input/output tokens, against $30 / $180 for GPT-5.4 Pro.
  • GPT-5.4 Pro accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Fable 5.1 and GPT-5.4 Pro specifications
Claude Fable 5.1GPT-5.4 Pro
ProviderAnthropicOpenAI
Noometry Index69.058.9
Released2026-09-012026-03-05
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$10$30
Output $ / M tokens$50$180
Results tracked5216

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), GPT-5.4 Pro: 43.2 (#90)

Coding benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
WeirdML92.9%57.4%
FrontierCode50.9%—
CursorBench51.8%—
LMArena WebDev1744—
FrontierSWE56.3%—
SciCode63.1%—
GSO88.2%—
LMArena Coding1528—
MirrorCode73.3%—
ALE-Bench2,143—

Agentic & Tool Use Not comparable

Claude Fable 5.1: 50.7 (#5), GPT-5.4 Pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
APEX-Agents68.6%—
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), GPT-5.4 Pro: 70.7 (#13)

Reasoning benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
ARC-AGI-290%83.3%
ARC-AGI-197.5%94.5%
CritPt31.1%30%
Chess Puzzles47%58.6%
Epoch Capabilities Index164.7158.93
SimpleBench—74.1%
NYT Connections (extended)90%—
EnigmaEval—23.8%
EBR-Bench57.1%—
LMArena Hard Prompts1526—
Mystery Game Puzzles58%—
DTBench97.6%—
LMCA65.5%—

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), GPT-5.4 Pro: 72.4 (#22)

Math benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
FrontierMath (Tiers 1-3)90.2%82.5%
FrontierMath Tier 487.8%58.5%
OTIS Mock AIME 2024-2025100%—
ProofBench100%—
LMArena Math1525—
FrontierMath (Feb 2025 set)—50%
FrontierMath Erdős0%—
FrontierMath Tier 4 (v1)—37.5%

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), GPT-5.4 Pro: 68.3 (#7)

Knowledge benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
Humanity's Last Exam46.5%44.3%
SimpleQA Verified70.8%46.3%
GPQA Diamond—94.6%
Vectara Hallucination Rate—8.3%
LMArena Expert1535—

Multimodal Not comparable

Claude Fable 5.1: 53.9 (#4), GPT-5.4 Pro: —

Multimodal benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
LMArena Vision1318—
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Not comparable

Claude Fable 5.1: 59.1 (#3), GPT-5.4 Pro: —

Multilingual benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
LMArena Non-English1507—
LMArena Chinese1586—
LMArena French1525—
LMArena German1500—
LMArena Japanese1543—
LMArena Korean1534—
LMArena Russian1521—
LMArena Spanish1516—

Instruction Following Not comparable

Claude Fable 5.1: 79.2 (#6), GPT-5.4 Pro: —

Instruction Following benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
LMArena Instruction Following1517—

Long Context Not comparable

Claude Fable 5.1: 46.7 (#20), GPT-5.4 Pro: —

Long Context benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
LMArena Longer Query1522—

Writing & Preference Not comparable

Claude Fable 5.1: 79.2 (#2), GPT-5.4 Pro: —

Writing & Preference benchmarks
BenchmarkClaude Fable 5.1GPT-5.4 Pro
LMArena Text1510—
LMArena Creative Writing1507—
EQ-Bench Creative Writing2162—
LMArena Multi-Turn1492—

Frequently asked questions

Is Claude Fable 5.1 better than GPT-5.4 Pro?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 58.9 on the Noometry Index.

Which is cheaper, Claude Fable 5.1 or GPT-5.4 Pro?

Claude Fable 5.1 is cheaper. It lists at $10 per million input tokens and $50 per million output tokens; GPT-5.4 Pro lists at $30 and $180.

Is Claude Fable 5.1 or GPT-5.4 Pro better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 43.2 in the Noometry coding category.

Which has the bigger context window?

GPT-5.4 Pro does, with 1.05M tokens against 1M.

How many benchmarks do Claude Fable 5.1 and GPT-5.4 Pro share?

10 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and GPT-5.4 Pro has 16.

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