Upstage unveils Solar Open 2, open-weight AI model built for autonomous tasks

Upstage, a South Korean AI company, released Solar Open 2, an open-weight large language model optimised for autonomous agent tasks with 250 billion parameters (15 billion active) and 1 million token context window. The model outperforms DeepSeek V4 Flash, Mistral Medium 3.5, and Cohere Command A+ on agent benchmarks, and beats OpenAI GPT-5.4 mini and Anthropic Claude Haiku 4.5 on Korean language tasks.

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