Microsoft just made GPT-5.6 the default brain powering its entire 365 Copilot suite. The integration went live on July 9 across Word, Excel, PowerPoint, Copilot Chat, and Cowork, making this a day-zero deployment that matched the model’s general availability in ChatGPT and Codex.
What GPT-5.6 actually changes
The upgrade targets what OpenAI and Microsoft are calling “complex, multi-step tasks.” Think option comparisons in Excel, structured planning documents in Word, troubleshooting workflows, and data analysis that previously required a human to stitch together multiple steps.
Early feedback from users and enterprise experts has pointed to improved performance per token, which is a technical way of saying the model does more useful work for every unit of compute it consumes.
Here’s the thing about the rollout mechanics: Microsoft is using automatic task routing, meaning the system decides which model handles which request based on optimization criteria. Users can also manually select GPT-5.6 where a model picker is available, but the default behavior is algorithmic matching. Some enterprise users have already raised concerns about transparency, specifically around not always knowing which model is handling their request.
