Copilot in Word Excel and PowerPoint starts offering extra AI models
Reviewed by Helen Jones
As of 22 September 2026, Microsoft is rolling Anthropic Claude Opus 5.5 and OpenAI GPT-6 Sol into Copilot in Word, Excel, PowerPoint, Copilot Chat, Cowork and Copilot Studio. A 25 September digest compiled from Microsoft sources reports the change as underway, not as a single overnight switch. Microsoft Learn notes for Cowork also list Claude Fable 5.1 and GPT 6 Astra in that app's model selector. Which names you see depends on the surface, and tenants get the picker on a gradual schedule. Where a model picker appears, output quality and speed can differ by model. Some frontier models may be usage-based, so cost can change if your organisation meters those choices.
Until this week, Copilot in the Office apps mostly hid the model. You judged the product by whether a draft, recap or table answer was usable, not by which lab's model sat behind the button. Switching to ChatGPT or Claude was a separate decision outside Microsoft 365 context. A picker inside Word, Excel and PowerPoint does not create a playbook. A stronger model can make a weak brief look finished, which raises review work if facts, tone and file context are still wrong. The useful change is a chance to compare models on the same real document, not a reason to treat every Copilot click as a new experiment.
Analysis
Treat this as a test, not a reset of how you use Copilot. When the picker shows up, rerun one prompt you already trust in Word or Excel on the default model and on Opus 5.5 or GPT-6 Sol, then keep the new model only if rewrite time drops while your usual review checklist still catches errors.
Source note
Pulse published by Collab365 Spaces, reviewed by Helen Jones on . Cite as "Copilot in Word Excel and PowerPoint starts offering extra AI models", Collab365 Spaces. 2 sources referenced.