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.
816B253B
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—
These models have no shared benchmark scores.
Overview
CompanyMetaNVIDIA
Release dateOct 15 2026Apr 8 2025
AccessOpen WeightOpen Weight
Model detailsView modelView model

Frequently asked questions

Muse Spark Open and Llama Nemotron Ultra 253B don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Llama Nemotron Ultra 253B shipped 555 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Muse Spark Open has 816B parameters, while Llama Nemotron Ultra 253B has 253B.

Direct benchmark comparisons are unavailable — Muse Spark Open and Llama Nemotron Ultra 253B don't publish scores on any of the same benchmarks.