Compare AI models

Specifications
Context window
1M1.05M
API pricing
Input price
$2.00$5.00
Output price
$10.00$30.00
Cached input price
$0.20$0.50
Cheapest input
—$2.50OpenAI
Cheapest output
—$15.00OpenAI
Benchmarks
Humanity's Last Exam · with tools
64.5%52.2%
Overview
CompanyAnthropicOpenAI
Release dateSep 28 2026Apr 23 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GPT-5.5 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 $5.00 per million input tokens, and $10.00 vs $30.00 per million output tokens. GPT-5.5 shipped 158 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-5.5).

On Humanity's Last Exam · with tools, Claude Sonnet 5.5 leads at 64.5% vs GPT-5.5 at 52.2%.