Compare AI models

Specifications
Context window
1M1.05M
API pricing
Input price
$2.00$0.10
Output price
$10.00$0.50
Cached input price
$0.20$0.01
Cheapest input
—$0.05OpenAI
Cheapest output
—$0.25OpenAI

These models have no shared benchmark scores.

Overview
CompanyAnthropicOpenAI
Release dateSep 28 2026Sep 22 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 and GPT-6 Luna don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-6 Luna is cheaper on both input and output: $0.10 vs $2.00 per million input tokens, and $0.50 vs $10.00 per million output tokens. Figures are base-tier rates. GPT-6 Luna shipped 6 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Sonnet 5.5) vs 1.05M (GPT-6 Luna).

Direct benchmark comparisons are unavailable — Claude Sonnet 5.5 and GPT-6 Luna don't publish scores on any of the same benchmarks.