Model Comparison

Fable 5.1 vs GPT 4.5

Fable 5.1 ranks #4 on the AI IQ leaderboard with an estimated IQ of 138, while GPT 4.5 ranks #157 on the AI IQ leaderboard with an estimated IQ of 83. 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 4.5OpenAI
Rank#4#157
IQ13883
Abstract Reasoning12471
Mathematical Reasoning14970
Academic Reasoning137119
Programmatic Reasoning14778
Computer Use14270
Reliability13684
Knowledge Work13384
Emotional Reasoning——
Effective Cost / 1M Tokens$88.21—
Sticker Price / 1M I/O Tokens$60.00—
Speed65 tok/s—
Context Window1M128K
Released2026-09-012025-02-27
Open WeightsNoNo