Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$2.00$0.20
Output price
$10.00$1.25
Cached input price
$0.20$0.02
Cheapest input
—$0.10OpenAI
Cheapest output
—$0.625OpenAI
Benchmarks
Humanity's Last Exam · with tools
64.5%37.7%
Overview
CompanyAnthropicOpenAI
Release dateSep 28 2026Mar 17 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GPT-5.4 nano on 1 of the 1 benchmark they both report (Humanity's Last Exam). GPT-5.4 nano is cheaper on both input and output: $0.20 vs $2.00 per million input tokens, and $1.25 vs $10.00 per million output tokens. GPT-5.4 nano shipped 195 days before Claude Sonnet 5.5, 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 Sonnet 5.5 leads at 64.5% vs GPT-5.4 nano at 37.7%.