Microsoft 365 Copilot Adds GPT-5.5 Thinking and ChatGPT Images 2.0

Microsoft is expanding Microsoft 365 Copilot with GPT-5.5 Thinking and ChatGPT Images 2.0, bringing OpenAI’s latest reasoning and image-generation capabilities into its workplace productivity suite.

The announcement, published on the official Microsoft 365 Copilot Blog on April 27, 2026, says the update is intended to strengthen Copilot’s support for deeper analysis, multi-step work, and visual creation. Microsoft says GPT-5.5 Thinking is now available in Copilot Studio early release cycle environments as GPT-5.5 Reasoning and is rolling out across Microsoft 365 Copilot in Copilot Chat, Word, Excel, and PowerPoint. The company also says ChatGPT Images 2.0 is rolling out to Copilot in PowerPoint and is coming soon to Copilot Chat.

A reasoning upgrade for Microsoft 365 Copilot

I see this rollout as a notable step in Microsoft’s effort to make Copilot more useful for work that requires more than short-form answers. Microsoft positions GPT-5.5 Thinking as a model suited to deeper analysis and multi-step work, which fits naturally with Copilot’s role across Word, Excel, PowerPoint, and chat-based workflows.

OpenAI’s own GPT-5.5 release provides further context. OpenAI describes GPT-5.5 as its smartest and most intuitive model yet, built for tasks including writing and debugging code, researching online, analyzing data, creating documents and spreadsheets, operating software, and moving across tools until a task is finished.

For Microsoft 365 users, the practical significance is that the newer reasoning model is being placed inside everyday productivity applications rather than remaining limited to standalone AI products. Microsoft says the update works together with Work IQ, its system for helping Copilot produce more focused and relevant outputs for analysis, creation, and complex work.

Microsoft has not provided detailed tenant-by-tenant timing, exact app-version requirements, or full rollout milestones in the announcement. From the wording Microsoft uses, I read this as a phased rollout rather than immediate universal availability.

ChatGPT Images 2.0 arrives first in PowerPoint

The visual part of the update begins with PowerPoint. Microsoft says ChatGPT Images 2.0 is rolling out to Copilot in PowerPoint, with Copilot Chat support planned later.

OpenAI introduced ChatGPT Images 2.0 on April 21, 2026, describing it as a new era of image generation. OpenAI’s examples emphasize greater precision and control, multilingual text rendering, realistic and stylized outputs, editorial layouts, manga-style panels, campaign-style assets, and multi-scene visual storytelling.

In my view, the PowerPoint integration is the most immediately practical part of the announcement. Presentations are rarely just text documents; they require structure, visual hierarchy, and supporting images. If the integration works as described, Copilot could become more useful in the full presentation-building process, not just in drafting slide copy.

However, Microsoft’s Copilot post does not specify detailed usage limits, whether availability differs between PowerPoint desktop and web, or how users can confirm which image model generated a particular asset.

What has been confirmed

Microsoft Learn documentation for early release cycle environments explains that these environments receive updates first so organizations can validate scenarios before updates reach business-critical apps. The same documentation notes that updates can take days or weeks to roll out across customer environments and regions, which is important context for customers tracking GPT-5.5 Reasoning availability in Copilot Studio.

OpenAI’s benchmark claims add context, but not Copilot-specific guarantees

OpenAI reports that GPT-5.5 shows gains in areas such as agentic coding, computer use, knowledge work, and scientific research. Its published results include 82.7% on Terminal-Bench 2.0, 58.6% on SWE-Bench Pro, 84.9% on GDPval wins or ties, and 78.7% on OSWorld-Verified.

I would treat those figures as useful technical context, not as direct Microsoft 365 Copilot benchmark results. Microsoft’s announcement confirms product integration and rollout status; it does not publish Copilot-specific performance measurements, context-window details, pricing, or user-facing reasoning controls.

My hands-on testing note

In my own hands-on testing, GPT-5.5 Thinking in Microsoft 365 Copilot appeared to operate with medium reasoning effort, based on an observed reasoning budget value of 24. I include this as a practical field note, but Microsoft has not officially documented a reasoning-effort setting, exposed a supported mapping for that value, or confirmed medium reasoning effort as a default for Microsoft 365 Copilot.

Because of that, I would separate the observation from the verified announcement. The verified claim remains narrower: Microsoft says GPT-5.5 Thinking is rolling out across Microsoft 365 Copilot, and GPT-5.5 Reasoning is available in Copilot Studio early release cycle environments.

A measured but important Copilot expansion

Microsoft’s announcement is concise, but I see it as a meaningful expansion of Copilot’s role in enterprise productivity. The platform is gaining a reasoning model that OpenAI says is better suited to sustained work, while PowerPoint is gaining a newer image model designed for more precise and controlled visual creation.

The main limitation is transparency. Microsoft has not yet detailed rollout schedules by tenant or region, usage limits for ChatGPT Images 2.0, app-version requirements, or a user-visible way to confirm model selection. Until those details are published, I would recommend treating availability as gradual and verifying access inside each Microsoft 365 environment.

The confirmed bottom line is that GPT-5.5 Thinking and ChatGPT Images 2.0 are now part of Microsoft’s Microsoft 365 Copilot expansion, with reasoning features moving across Copilot Chat and core Office apps, and image generation beginning in PowerPoint before reaching Copilot Chat.