GitHub Copilot App Gets Built-In Diff, Terminal, and Browser Panels

GitHub has added three built-in panels to its Copilot app: a diff viewer, an integrated terminal, and a browser preview. Together they let developers review what an AI agent changed, run the code, and test the result, all without switching between their editor, a terminal window, and a browser tab. The feature is aimed at beginners but solves a workflow problem that affects anyone using AI-assisted coding agents.

What happened

Panel	What it does
Diff	Shows added lines in green and removed lines in red; lets you accept, comment, or request further changes
Terminal	Runs project commands inside the session; supports multiple windows and a configurable Run button
Browser	Renders a live preview of UI changes; includes a Pick & Polish tool for iterating on elements with the agent

GitHub has shipped three side-by-side panels inside the Copilot app that cover the full review cycle for agent-generated code. Previously, verifying an agent’s work meant jumping between at least three separate programs. Now the process stays in one place.

The diff panel works like a standard code review tool. Green lines are additions, red lines are deletions. You stay in control: you can accept the changes, leave a comment for the agent, or ask it to revise before anything gets merged.

How the terminal and browser panels work

The terminal panel lets you run commands without opening a separate terminal application. According to GitHub, you can either run commands manually or wire up a script to the Run button. Their example uses a dev server: add a script that opens the client folder and runs npm run dev, then click Run to start it. You can keep multiple terminal windows open simultaneously and switch between them.

The browser panel is for anything with a visible interface. Once your dev server is running, the panel loads the site so you can click around and verify the new feature works as expected. The Pick & Polish tool lets you select a specific UI element and send targeted instructions back to the agent, tightening the iteration loop further.

Why it matters

AI coding agents can produce plausible-looking code that still breaks at runtime or looks wrong in a real browser. The standard advice has always been: review the diff, run the code, check the UI. The friction was that those three steps required three different contexts, and context-switching is where mistakes get missed.

Consolidating them into one app lowers that friction enough that developers, especially less experienced ones, are more likely to complete the full check before hitting accept. That is the gap GitHub is trying to close.

For teams already using GitHub Copilot for AI integration in their development workflow, this reduces the overhead of agent-assisted coding without requiring any new tooling or configuration.

Our take

This is a sensible quality-of-life improvement, not a capability leap. The panels do not add new AI power; they reduce the number of reasons to ignore a proper review. That is actually more valuable in practice.

The three questions GitHub suggests you ask before accepting agent code are worth keeping: What changed? Does it run? Does it actually work? Those questions existed before Copilot, and they will matter long after the tooling changes again. What the new panels do is make answering them cheaper, so fewer people skip the step.

If you are onboarding junior developers or non-engineers who use Copilot to generate code they do not fully understand, this setup gives them a structured review habit built into the tool itself. That is worth something. We have written before about the broader pattern of GitHub embedding AI review directly into the pull request workflow, and this follows the same direction: shrink the gap between code generation and confident merge.

What to do about it

1. Open the GitHub Copilot app and locate the diff, terminal, and browser panel tabs if you have not already.
2. Before accepting any agent change, run through the three checks: read the diff, run the project in the terminal panel, and test the UI in the browser panel.
3. Set up your dev server command as a script on the Run button so the terminal step takes one click, not a typed command.
4. Use Pick & Polish for UI tweaks instead of writing out full prompts; it keeps iterations fast and targeted.
5. Once all three checks pass, accept the change and create the pull request directly from the app.

The quickest way to build trust in agent-generated code is to verify it every time, and these panels make that the path of least resistance.

Source: GitHub Blog