Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$10.00—
Output price
$50.00—
Cached input price
$0.25—
Cheapest input
$10.00Amazon Bedrock—
Cheapest output
$50.00Amazon Bedrock—
Benchmarks
BullshitBench v2
77%39%
Overview
CompanyAnthropicOpenAI
Release dateSep 1 2026Sep 15 2025
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GPT-5-Codex on 1 of the 1 benchmark they both report (BullshitBench v2). Only Claude Fable 5.1 has a verified first-party API price: $10.00 per million input tokens and $50.00 per million output tokens. No pay-as-you-go API rate is tracked for GPT-5-Codex. GPT-5-Codex shipped 351 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 BullshitBench v2, Claude Fable 5.1 leads at 77% vs GPT-5-Codex at 39%.