Model Comparison

Fable 5.1 vs Opus 4

Fable 5.1 ranks #6 on the AI IQ leaderboard with an estimated IQ of 137, while Opus 4 ranks #149 on the AI IQ leaderboard with an estimated IQ of 95. 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 5.1AnthropicOpus 4Anthropic
Rank#6#149
IQ13795
Abstract Reasoning12477
Mathematical Reasoning14793
Academic Reasoning136112
Programmatic Reasoning146109
Computer Use14175
Reliability135109
Knowledge Work13290
Emotional Reasoning——
Effective Cost / 1M Tokens$91.05$51.65
Sticker Price / 1M I/O Tokens$60.00$90.00
Speed70 tok/s—
Context Window1M—
Released2026-09-012025-05-22
Open WeightsNoNo