Model Comparison

Fable 5.1 vs GPT 5.4 Nano

Fable 5.1 ranks #5 on the AI IQ leaderboard with an estimated IQ of 137, while GPT 5.4 Nano ranks #91 on the AI IQ leaderboard with an estimated IQ of 106. The table below puts the two models side by side across the seven capability dimensions, emotional reasoning, cost, speed, and context window.

Where They Sit on the IQ Bell Curve
Both models highlighted on the standard normal IQ distribution of every tracked model
IQ Dimensions Head to Head
The seven scored Composite IQ dimensions, side by side
Domains Head to Head
Applied domain composite scores where at least one model is measured
Fable 5.1AnthropicGPT 5.4 NanoOpenAI
Rank#5#91
IQ137106
Abstract Reasoning12485
Mathematical Reasoning148113
Academic Reasoning136120
Programmatic Reasoning147110
Computer Use140104
Reliability135102
Knowledge Work133109
Emotional Reasoning——
Effective Cost / 1M Tokens$90.82$1.63
Sticker Price / 1M I/O Tokens$60.00$1.45
Speed68 tok/s166 tok/s
Context Window1M400K
Released2026-09-012026-03-17
Open WeightsNoNo