Compare AI models

Specifications
ParametersThe learned values that shape how a model responds. B means billion and T means trillion. For mixture-of-experts models, the total count is larger than the number active for each token. Parameter count alone does not measure quality.
—320B
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
—1M
API pricingUSD per 1M tokens · lower wins
Cheapest inputLowest input rate across every provider on OpenRouter, the lab included. The cheapest endpoint may run a quantised build or a shorter context — see "Available from" on the model page.
—$0.0285Relace
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$0.0923Relace
—$10.32Relace · fp4
Benchmarks
Humanity's Last Exam · with toolsMultidisciplinary reasoning — Humanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better.
35%55.3%
Overview
CompanySpaceXSIZ.ai
Release dateApr 17 2026Aug 26 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

GLM-5.3-Flash leads Grok 4.3 Beta on 1 of the 1 benchmark they both report (Humanity's Last Exam). Grok 4.3 Beta shipped 131 days before GLM-5.3-Flash, so benchmark comparisons should account for the intervening progress.

Grok 4.3 Beta is closed, while GLM-5.3-Flash is open weight.

On Humanity's Last Exam · with tools, GLM-5.3-Flash leads at 55.3% vs Grok 4.3 Beta at 35%.