GitHub Copilot app adds diff, terminal, browser panels

The post is aimed at beginners using the GitHub Copilot app, and it frames the update as a way to complete the AI coding loop from one window. Previously, checking an agent's work meant moving between an editor, a terminal, and a browser; now those three views are built-in panels in the same app. The article walks through a website example, adding a dev server script that opens the client folder and runs npm run dev, then using the browser panel to test the feature as if using the site.

The diff panel is described as the place to see exactly what an agent changed, with green additions and red deletions, and it lets you accept changes, leave comments, or ask Copilot for edits. The terminal panel is for running the project's own commands, and the browser panel closes the loop for anything with a user interface, including the Pick & Polish tool for selecting an element and adjusting it with the agent. Together they are presented as answering three questions: what changed, does it run, and does it actually work.

The stakes depend on whether seeing review, run, and preview side by side makes agent-made changes feel safe rather than scary for less experienced users. The article presents the panels as a way to prove that what you merge works before you accept it and open a pull request. GitHub Universe 2026 is noted as October 28-29 in San Francisco or online, though the post does not tie the panels to that event.