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.
816B550B
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—
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.
—$0.50DeepInfra
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$2.20DeepInfra
—$210DeepInfra · fp4
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%56.4%
Overview
CompanyMetaNVIDIA
Release dateOct 15 2026Jun 4 2026
AccessOpen WeightOpen Source
Model detailsView modelView model

Frequently asked questions

Muse Spark Open leads Nemotron 3 Ultra on 1 of the 1 benchmark they both report (Terminal-Bench 2.1). Nemotron 3 Ultra shipped 133 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Muse Spark Open has 816B parameters, while Nemotron 3 Ultra has 550B. Muse Spark Open is open weight, while Nemotron 3 Ultra is open source.

On Terminal-Bench 2.1, Muse Spark Open leads at 76.4% vs Nemotron 3 Ultra at 56.4%.