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—
API pricingUSD per 1M tokens · lower wins · base tier
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
—$1.00
Output priceWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
—$2.00
Cached input priceA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
—$0.20
—$300SpaceXSI list price
These models have no shared benchmark scores.
Overview
CompanyMetaSpaceXSI
Release dateOct 15 2026Aug 28 2025
AccessOpen WeightClosed
Model detailsView modelView model

Frequently asked questions

Muse Spark Open and Grok Code Fast 1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Only Grok Code Fast 1 has a verified first-party API price: $1.00 per million input tokens and $2.00 per million output tokens. No pay-as-you-go API rate is tracked for Muse Spark Open. Grok Code Fast 1 shipped 413 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Muse Spark Open is open weight, while Grok Code Fast 1 is closed.

Direct benchmark comparisons are unavailable — Muse Spark Open and Grok Code Fast 1 don't publish scores on any of the same benchmarks.