Microsoft is bringing the power of large language models (LLMs) directly into Excel cells through a new feature called "Copilot," aiming to fundamentally change how users handle data. This integration will speed up tasks such as data analysis, text classification, and content generation, allowing users to complete them without manual editing or relying on external tools.

Easy to Use, Powerful Functionality

The new Copilot feature can be used with a simple formula =COPILOT(prompt_part1, [context1], ...). Users just need to input a request in simple English and specify a cell range as context, and Copilot will complete complex tasks directly within Excel cells. For example, use =COPILOT("Classify this feedback", D4:D18) to classify customer feedback, or search for airport codes across the United States based on a prompt.

This feature is built into Excel's calculation engine, which means that AI results automatically update when data changes, without the need for manual refreshing. It can also be combined with other Excel formulas like IF, SWITCH, and LAMBDA, greatly expanding its application scenarios.

Microsoft lists several core application cases:

  • Content Generation: Transform product descriptions into SEO keywords or rewrite marketing copy.

  • Data Summary: Summarize large datasets or convert complex calculation results into easy-to-understand reports.

  • Text Classification: Efficiently classify customer feedback, support tickets, or survey responses.

  • List Creation: Generate test data, industry benchmarks, or project plans based on existing data models.

Data Privacy and Usage Limits

Microsoft emphasizes that data sent through Copilot will not be used to train its AI models, and all information will remain private. Currently, Copilot cannot access real-time web data or company internal files, relying only on its pre-trained knowledge, but Microsoft plans to lift these restrictions in the future.

In terms of usage, the feature can be called up to 100 times every ten minutes and up to 300 times per hour. To maximize efficiency, Microsoft recommends using arrays rather than individual cells, as even if a larger data range is processed, it will only count as one call.

Currently Available Only in Beta Version

Currently, this new feature is available only to Beta channel users with a Microsoft 365 Copilot license. Users need to install specific versions of Windows or Mac, and the web version will soon be launched via the Frontier project.

Microsoft is continuously improving this feature, including supporting larger arrays and improving date handling. Although it is unclear which specific OpenAI model is used underneath, it is likely the GPT-4o used for other Office features, and future plans include upgrading to the GPT-5 series.

This built-in cell function represents a significant advancement compared to the previous Copilot version as a standalone sidebar. It eliminates the hassle of switching back and forth between the chat interface and spreadsheet, making workflows more seamless and efficient.