Solar Open 2 (250B)
Solar Open 2 is an open-weight hybrid-attention mixture-of-experts model from Upstage, released on July 22, 2026 for agentic use (office productivity, document-intensive work and coding), with official support for Korean, English and Japanese. Upstage’s closed-beta API for it ran from July 8 to August 12, 2026; the open weights remain available.
Released
July 22, 2026
Type
llm
License
open-weight
Upstage Solar License
Context
—
The developer states a context window of “1M” tokens.
Capabilities
textdocumentstoolscodemultilingual
Architecture
Parameters: 250B total, 15B active (Mixture of Experts)
Sources
Every figure on this page was checked against these pages on . A figure we could not source is left out.
- Upstage blog: Solar Open 2 (opens in a new tab)
- Hugging Face: upstage/Solar-Open2-250B (opens in a new tab)
- Solar Open 2 Technical Report (arXiv 2607.20062) (opens in a new tab)
- Upstage docs: Model history (opens in a new tab)
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