Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$10.00$30.00
Output price
$50.00$180.00
Cached input price
$0.25—
Cheapest input
$10.00Amazon Bedrock$15.00OpenAI
Cheapest output
$50.00Amazon Bedrock$90.00OpenAI
Benchmarks
Humanity's Last Exam · with tools
65.6%58.7%
ARC-AGI-2
90%83.3%
Overview
CompanyAnthropicOpenAI
Release dateSep 1 2026Mar 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GPT-5.4-Pro on 2 of the 2 benchmarks they both report (Humanity's Last Exam, ARC-AGI-2). Claude Fable 5.1 is cheaper on both input and output: $10.00 vs $30.00 per million input tokens, and $50.00 vs $180.00 per million output tokens. GPT-5.4-Pro shipped 180 days before Claude Fable 5.1, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On Humanity's Last Exam · with tools, Claude Fable 5.1 leads at 65.6% vs GPT-5.4-Pro at 58.7%. On ARC-AGI-2, Claude Fable 5.1 leads at 90% vs GPT-5.4-Pro at 83.3%.