The OpenAI o1 model has been integrated into Microsoft’s Copilot AI experience, allowing users of Microsoft 365 to utilize it free of charge via a new feature known as ‘Think Deeper’. This toggle is now accessible within Copilot chat.
Recently, Mustafa Suleyman, Microsoft’s AI chief, shared insights into this exciting new feature on LinkedIn. The Think Deeper function is designed to offer guidance, aid in planning, and facilitate in-depth exploration of various subjects, among other capabilities. Unlike other functionalities of Copilot that are integrated into Microsoft 365 desktop applications, Think Deeper can be accessed via the Copilot web chat at copilot.microsoft.com or the downloadable Copilot app. Users must have a Microsoft account to use this feature.

Engaging with Think Deeper is straightforward. Simply navigate to the web page, where you’ll find an option for easy sign-on to your Microsoft account. After logging in, you’ll arrive at the Copilot welcome page. Click the small Copilot icon located in the corner of the text box; it will switch to a black-highlighted ‘Think Deeper’ icon, signifying that the feature is activated. Enter your questions and let Copilot do the rest.
When OpenAI unveiled the o1 model in December 2024, it was noted for its impressive capabilities, solving Mathematics Olympiad problems with an accuracy of 86% and demonstrating PhD-level proficiency in STEM subjects.
To test the feature, I posed a mathematics problem typically found on the SAT. On my initial try without the Think Deeper toggle activated, Copilot provided a clear but straightforward response detailing the solution. However, when I enabled the Think Deeper option, the results were significantly more comprehensive—Copilot not only delivered the correct answer but also included a psychological assessment of the topic, historical context surrounding the problem, and intriguing facts related to it. Overall, the depth of this response far exceeded the initial explanation.

Previously, access to the o1 model was limited to paid tiers offered by OpenAI. The service has a hefty price tag of $200 per month for ChatGPT Pro, which includes complete access to this model, while ChatGPT Plus offers limited access for $20 per month.
Although the Think Deeper function and OpenAI o1 model are now available for free to all Microsoft users, many have noted that Microsoft 365 subscribers were recently informed of an upcoming price increase on personal plans, which will take effect during the next renewal period.