Model Comparison

Fable 5.2 vs Opus 5.5

Fable 5.2 ranks #1 on the AI IQ leaderboard with an estimated IQ of 144, while Opus 5.5 ranks #4 on the AI IQ leaderboard with an estimated IQ of 140. 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 5.2AnthropicOpus 5.5Anthropic
Rank#1#4
IQ144140
Abstract Reasoning134132
Mathematical Reasoning148148
Academic Reasoning135138
Programmatic Reasoning154154
Computer Use157143
Reliability145132
Knowledge Work134134
Emotional Reasoning——
Effective Cost / 1M Tokens$73.69$35.97
Sticker Price / 1M I/O Tokens$48.00$24.00
Speed—98 tok/s
Context Window1M1M
Released2026-11-092026-09-22
Open WeightsNoNo