Overview

• OpenAI has published gpt-oss-120b and gpt-oss-20b, its first fully open-weight models since 2020, under permissive licenses for public download and adaptation.
• The models employ a mixture-of-experts architecture that activates 12 of 64 experts, while keeping routing mechanisms and training data proprietary.
• Enterprise partners including Orange and Snowflake have begun trials integrating the open-weight models into their workflows.
• GPT-5 is now the default ChatGPT engine across Free, Plus and Pro plans, with free users capped then shifted to a GPT-5 mini fallback, Plus users granted higher limits, and Pro subscribers receiving unlimited access to GPT-5 Pro.
• OpenAI presents these releases as dual milestones on its path to AGI, aiming to satisfy transparency demands and counter competition from rivals such as DeepSeek and Alibaba’s Qwen.