Microsoft rolls out advanced OpenAI model to 365 Copilot apps

Microsoft has added GPT-5.5 Thinking, a model focused on step-by-step reasoning, to Copilot Chat, Word, Excel and PowerPoint. It appears as GPT-5.5 Reasoning in early Copilot Studio environments. The update started rolling out today. ChatGPT Images 2.0, which generates and edits visuals from text, launches first in PowerPoint Copilot. It will reach Copilot Chat soon. Both features aim to handle complex analysis and creative tasks better. Microsoft says the changes improve multi-step problem-solving and output quality in daily apps.
Copilot users often ditched it for ChatGPT because responses felt shallow on chained tasks like data breakdowns or report chaining, especially without M365 data grounding. Teams leads struggled to demo reliable wins, fueling secret ChatGPT use and sub-10% adoption. GPT-5.5 Thinking now matches that depth natively in apps, pulling from your company's files for grounded results that ChatGPT cannot match without risky uploads. This shifts Copilot from 'corporate filler' to a tool that visibly saves time on real work, easing boss pressure for ROI proof.
Analysis
Forget the hype—this upgrade finally gives Copilot the reasoning muscle to beat ChatGPT on your own files without governance risks, but only if your prompts demand multi-step logic. Test it right now in Excel on a pivot table analysis that flopped before: paste data, prompt 'Break this into trends, forecast next quarter, flag outliers with reasons,' then screenshot the before/after vs ChatGPT for your next standup.
Citation
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