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.
816B30B
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.
—$0.025Darkbloom
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$0.12Darkbloom
—$11.00Darkbloom · int4
These models have no shared benchmark scores.
Overview
CompanyMetaNVIDIA
Release dateOct 15 2026Aug 11 2026
AccessOpen WeightOpen Source
Model detailsView modelView model

Frequently asked questions

Muse Spark Open and Nemotron 3.5 Lightning don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Nemotron 3.5 Lightning shipped 65 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Muse Spark Open has 816B parameters, while Nemotron 3.5 Lightning has 30B. Context windows are 1M (Muse Spark Open) vs 1M (Nemotron 3.5 Lightning). Muse Spark Open is open weight, while Nemotron 3.5 Lightning is open source.

Direct benchmark comparisons are unavailable — Muse Spark Open and Nemotron 3.5 Lightning don't publish scores on any of the same benchmarks.