Compare AI models

Specifications
Context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.
1M1M
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.
—$1.25
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.
—$4.25
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.
—$0.15
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.
—$1.25Meta
Cheapest outputLowest output rate across every provider on OpenRouter, the lab included. May come from a different provider than the cheapest input.
—$4.25Meta
—$463Meta list price
Benchmarks
CharXiv Reasoning · with toolsChart reasoning — The same chart-and-figure reasoning test, run with the AI allowed to use tools — writing code to inspect the image, for instance — rather than reading the chart unaided. Scores run higher than the unaided version, so read the two as separate tests. Higher is better.
93.2%87.6%
Overview
CompanyAnthropicMeta
Release dateApr 7 2026Aug 5 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Mythos Preview leads Muse Spark 1.2 on 1 of the 1 benchmark they both report (CharXiv Reasoning). Only Muse Spark 1.2 has a verified first-party price for an available API: $1.25 per million input tokens and $4.25 per million output tokens. No currently available pay-as-you-go API rate is tracked for Claude Mythos Preview. Claude Mythos Preview shipped 120 days before Muse Spark 1.2, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Mythos Preview) vs 1M (Muse Spark 1.2).

On CharXiv Reasoning · with tools, Claude Mythos Preview leads at 93.2% vs Muse Spark 1.2 at 87.6%.