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.
816B—
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.
1M—
Benchmarks
Terminal-Bench 2.1Agentic terminal coding — Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better.
76.4%73%
Overview
CompanyMetaSpaceXSI
Release dateOct 15 2026May 18 2026
AccessOpen WeightClosed
Model detailsView modelView model

Frequently asked questions

Muse Spark Open leads Composer 2.5 on 1 of the 1 benchmark they both report (Terminal-Bench 2.1). Composer 2.5 shipped 150 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Muse Spark Open is open weight, while Composer 2.5 is closed.

On Terminal-Bench 2.1, Muse Spark Open leads at 76.4% vs Composer 2.5 at 73%.