OpenAI is launching a new lightweight version of the deep learning feature in ChatGPT. It is available to all users for free, but has usage limits.
For paid users, the light version will automatically be enabled when the full Deep Research usage limit is reached. "Answers will be shorter, but will retain the same depth and quality you're used to," OpenAI notes.
The tool is powered by the o4-mini model, a simplified version of the large o4 model that provides lower query processing overhead, allowing OpenAI to increase usage limits.