Muse Glimmervsgpt-oss-20b

Muse Glimmer
gpt-oss-20b
Specifications
Parameters
30B
21B
Context window
128k
Benchmarks
Agentic coding
SWE-Bench Pro
51.2%
Coding
SWE-Bench Verified
76%Best
60.7%
Agentic terminal coding
Terminal-Bench 2.1
51.7%
Multi-step tool use
MCP Atlas
75.5%
Multidisciplinary reasoning
Humanity's Last Exam · no tools
22%Best
10.9%
Multidisciplinary reasoning
Humanity's Last Exam · with tools
17.3%
Science
GPQA Diamond
83.5%Best
71.5%
General knowledge
MMLU
85.3%
Agentic computer use
OSWorld-Verified
65.9%
Knowledge work
GDPval-AA v2
953
Chart reasoning
CharXiv Reasoning
78.8%
Multimodal reasoning
MMMU-Pro
74%
Overview
CompanyMetaOpenAI
Release dateAug 10 2026Aug 5 2025
AccessOpen WeightOpen Weight

Which is better: Muse Glimmer or gpt-oss-20b?

Muse Glimmer leads gpt-oss-20b on 3 of the 3 benchmarks they both report (SWE-Bench Verified, Humanity's Last Exam, GPQA Diamond). gpt-oss-20b shipped 370 days before Muse Glimmer, so benchmark comparisons should account for the intervening progress.

Muse Glimmer has 30B parameters, while gpt-oss-20b has 21B.

On SWE-Bench Verified, Muse Glimmer leads at 76% vs gpt-oss-20b at 60.7%. On Humanity's Last Exam · no tools, Muse Glimmer leads at 22% vs gpt-oss-20b at 10.9%. On GPQA Diamond, Muse Glimmer leads at 83.5% vs gpt-oss-20b at 71.5%.

Frequently asked questions

Muse Glimmer was released by Meta on Aug 10 2026.

gpt-oss-20b was released by OpenAI on Aug 5 2025.

Muse Glimmer leads on SWE-Bench Verified — Muse Glimmer 76% vs gpt-oss-20b 60.7%.

Muse Glimmer leads on Humanity's Last Exam · no tools — Muse Glimmer 22% vs gpt-oss-20b 10.9%.

Other comparisons