Compare AI models

Specifications
Context window
1M—
API pricing
Input price
$2.00—
Output price
$10.00—
Cached input price
$0.20—
Benchmarks
Humanity's Last Exam · with tools
64.5%50.4%
Overview
CompanyAnthropicMeta
Release dateSep 28 2026Apr 8 2026
AccessClosedClosed
Model detailsView modelView model

Frequently asked questions

Claude Sonnet 5.5 leads Muse Spark on 1 of the 1 benchmark they both report (Humanity's Last Exam). Only Claude Sonnet 5.5 has a verified first-party API price: $2.00 per million input tokens and $10.00 per million output tokens. No pay-as-you-go API rate is tracked for Muse Spark. Muse Spark shipped 173 days before Claude Sonnet 5.5, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

On Humanity's Last Exam · with tools, Claude Sonnet 5.5 leads at 64.5% vs Muse Spark at 50.4%.