Compare AI models

Specifications
Parameters
—320B
Context window
1M1M
API pricing
Input price
$2.00—
Output price
$10.00—
Cached input price
$0.20—
Cheapest input
—$0.045InferenceNet
Cheapest output
—$0.14InferenceNet
Benchmarks
Humanity's Last Exam · with tools
64.5%55.3%
Overview
CompanyAnthropicZ.ai
Release dateSep 28 2026Aug 26 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads GLM-5.3-Flash on 1 of the 1 benchmark they both report (Humanity's Last Exam). Only Claude Sonnet 5.5 has a verified first-party API price: $2.00 per million input tokens and $10.00 per million output tokens. No pay-as-you-go API rate is tracked for GLM-5.3-Flash. GLM-5.3-Flash shipped 33 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Sonnet 5.5) vs 1M (GLM-5.3-Flash). Claude Sonnet 5.5 is closed, while GLM-5.3-Flash is open weight.

On Humanity's Last Exam · with tools, Claude Sonnet 5.5 leads at 64.5% vs GLM-5.3-Flash at 55.3%.