Compare AI models

Specifications
Parameters
—744B
Context window
1M200k
API pricing
Input price
$2.00$1.40
Output price
$10.00$4.40
Cached input price
$0.20$0.26
Cheapest input
—$0.966StreamLake
Cheapest output
—$3.036StreamLake
Benchmarks
Humanity's Last Exam · with tools
64.5%52.3%
Overview
CompanyAnthropicZ.ai
Release dateSep 28 2026Apr 7 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GLM-5.1 on 1 of the 1 benchmark they both report (Humanity's Last Exam). GLM-5.1 is cheaper on both input and output: $1.40 vs $2.00 per million input tokens, and $4.40 vs $10.00 per million output tokens. GLM-5.1 shipped 174 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Sonnet 5.5) vs 200k (GLM-5.1). Claude Sonnet 5.5 is closed, while GLM-5.1 is open weight.

On Humanity's Last Exam · with tools, Claude Sonnet 5.5 leads at 64.5% vs GLM-5.1 at 52.3%.