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
Input priceWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
$3.00—
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.
$15.00—
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.
$0.30—
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.
$3.00Amazon Bedrock—
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
$15.00Amazon Bedrock—
$1,350Anthropic list price—
Benchmarks
DeepSWE 1.1Agentic coding — Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. (Version 1.1 of the test.) Higher is better.
30%60%
MCP AtlasMulti-step tool use — Can the AI chain together many tools and steps to complete one bigger task, rather than doing just a single thing? Higher is better.
69.5%89.2%
Overview
CompanyAnthropicMeta
Release dateFeb 17 2026Oct 15 2026
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Muse Spark Open leads Claude Sonnet 4.6 on 2 of the 2 benchmarks they both report (DeepSWE 1.1, MCP Atlas). Only Claude Sonnet 4.6 has a verified first-party API price: $3.00 per million input tokens and $15.00 per million output tokens. No pay-as-you-go API rate is tracked for Muse Spark Open. Claude Sonnet 4.6 shipped 240 days before Muse Spark Open, so benchmark comparisons should account for the intervening progress.

Claude Sonnet 4.6 is closed, while Muse Spark Open is open weight.

On DeepSWE 1.1, Muse Spark Open leads at 60% vs Claude Sonnet 4.6 at 30%. On MCP Atlas, Muse Spark Open leads at 89.2% vs Claude Sonnet 4.6 at 69.5%.