Compare AI models

Specifications
Parameters
—21B
Context window
—128k
API pricing
Input price
$1.25—
Output price
$4.25—
Cheapest input
$1.25Meta$0.018Darkbloom
Cheapest output
$4.25Meta$0.09Darkbloom
Benchmarks
Humanity's Last Exam · with tools
62.1%17.3%
Overview
CompanyMetaOpenAI
Release dateJul 9 2026Aug 5 2025
AccessClosedOpen Weight
Model detailsView modelView model

Frequently asked questions

Muse Spark 1.1 leads gpt-oss-20b on 1 of the 1 benchmark they both report (Humanity's Last Exam). Only Muse Spark 1.1 has a verified first-party API price: $1.25 per million input tokens and $4.25 per million output tokens. No pay-as-you-go API rate is tracked for gpt-oss-20b. gpt-oss-20b shipped 338 days before Muse Spark 1.1, so benchmark comparisons should account for the intervening progress.

Muse Spark 1.1 is closed, while gpt-oss-20b is open weight.

On Humanity's Last Exam · with tools, Muse Spark 1.1 leads at 62.1% vs gpt-oss-20b at 17.3%.