Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$2.00$30.00
Output price
$10.00$180.00
Cached input price
$0.20—
Cheapest input
—$15.00OpenAI
Cheapest output
—$90.00OpenAI
Benchmarks
Humanity's Last Exam · with tools
64.5%58.7%
Overview
CompanyAnthropicOpenAI
Release dateSep 28 2026Mar 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GPT-5.4-Pro on 1 of the 1 benchmark they both report (Humanity's Last Exam). Claude Sonnet 5.5 is cheaper on both input and output: $2.00 vs $30.00 per million input tokens, and $10.00 vs $180.00 per million output tokens. GPT-5.4-Pro shipped 207 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-Pro at 58.7%.