Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$10.00$0.20
Output price
$50.00$1.20
Cached input price
$0.25$0.02
Cheapest input
$10.00Amazon Bedrock$0.10OpenAI
Cheapest output
$50.00Amazon Bedrock$0.60OpenAI
Benchmarks
BullshitBench v2
77%41%
CursorBench 4.0
51.8%35.9%
Terminal-Bench 4.0
57.88%17.27%
ARC-AGI-2
90%59.54%
threejseval
18561282
Overview
CompanyAnthropicOpenAI
Release dateSep 1 2026Jun 26 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Fable 5.1 leads GPT-5.6 Luna on 5 of the 5 benchmarks they both report. GPT-5.6 Luna is cheaper on both input and output: $0.20 vs $10.00 per million input tokens, and $1.20 vs $50.00 per million output tokens. Figures are base-tier rates. GPT-5.6 Luna shipped 67 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-5.6 Luna at 41%. On CursorBench 4.0, Claude Fable 5.1 leads at 51.8% vs GPT-5.6 Luna at 35.9%. On Terminal-Bench 4.0, Claude Fable 5.1 leads at 57.88% vs GPT-5.6 Luna at 17.27%. On ARC-AGI-2, Claude Fable 5.1 leads at 90% vs GPT-5.6 Luna at 59.54%. On threejseval, Claude Fable 5.1 leads at 1856 vs GPT-5.6 Luna at 1282.