Compare AI models

Specifications
ParametersA rough measure of how big the model is. More parameters usually means more capable and more expensive to run, though it is a poor guide on its own — a smaller, newer model often beats a larger, older one.
—320B
Context windowHow much text the model can hold in mind at once — your question, any documents you attach, the conversation so far, and its own reply. Go past it and the earliest part falls out of view.
1M1M
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.
—$0.0193OpenInference
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$0.145StreamLake
—$15.95StreamLake · fp8
Benchmarks
Terminal-Bench 4.0Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Version 4.0 recalibrated how much time, CPU and memory each task gets, removed eight tasks and fixed nineteen, so fewer runs fail for reasons that have nothing to do with the model. Scores are not comparable with earlier versions. Higher is better.
60.9%35.76%
Overview
CompanyAnthropicZ.ai
Release dateSep 1 2026Aug 26 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Claude Mythos 5.1 leads GLM-5.3-Flash on 1 of the 1 benchmark they both report (Terminal-Bench 4.0). GLM-5.3-Flash shipped 6 days before Claude Mythos 5.1, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Mythos 5.1) vs 1M (GLM-5.3-Flash). Claude Mythos 5.1 is closed, while GLM-5.3-Flash is open weight.

On Terminal-Bench 4.0, Claude Mythos 5.1 leads at 60.9% vs GLM-5.3-Flash at 35.76%.