OpenAI Announces o3 Pro, Its Smartest Reasoning Model Ever

OpenAI has officially launched o3-pro, a leading AI reasoning model that uses higher computing power to 'think deeper' and provide answers with superior quality. This new model will replace o1-pro on the ChatGPT platform , featuring greatly improved performance in the fields of mathematics, science, and programming.

To optimize the user experience, o3-pro supports tool calling. Based on the request, the model can perform web searches, analyze files, process image data, use Python, personalize responses using memory, and more. This is a big improvement over o1-pro, which does not support this feature. However, o3-pro will take longer to respond. OpenAI recommends users prioritize o3-pro when they want to access content that emphasizes reliability over response speed.

According to internal evaluation, o3-pro's response quality was significantly better than o3's in key areas such as science, education, programming, business, and writing support. o3-pro was also noted to be superior in clarity, comprehensiveness, adherence to instructions, and accuracy.

The new o3-pro model is available in the ChatGPT model selector for Pro and Team plans. Enterprise and Edu users will get access to this model next week.

For developers, o3-pro comes with a 200,000 token context window at $20/million input tokens, and $80/million output tokens. OpenAI recommends using background mode to avoid timeouts. The model has a knowledge limit until May 31, 2024.

The OpenAI team also highlighted the current limitations of o3-pro:

1. Temporary chats are temporarily unavailable due to technical issues.
2. Image generation is not supported in o3-pro — please use GPT-4o, OpenAI o3, or OpenAI o4-mini to generate images.
3. Canvas is not supported on this version.

As OpenAI continues to refine its models, the balance between speed and reliability will remain key to choosing the right tool for your needs.

Marvin Fry

Update 11 June 2025