Review Code in Split-Screen While You Chat

As of February 2026, ChatGPT's code blocks became fully interactive: you can write, edit, and preview code directly in chat without copying text back and forth to your editor. More importantly, the split-screen code review view lets you see your code on one side and your conversation on the other, making it easy to ask for targeted fixes and see them annotated in place.

Here's the professional workflow: You paste a Python function into ChatGPT. The code block opens on the right side. You ask "review this function for performance and edge cases." ChatGPT annotates the code with inline comments flagging specific lines-"This loop is O(n²), consider sorting first" or "Missing check for empty input." You then ask "fix the loop" and see just that section rewrite itself without touching the rest of the function. No diff-ing required. No manual reconciliation of changes.

The split-screen view works natively with HTML, React, Python, JavaScript, Mermaid diagrams, and Vega charts. Click "Review code" to get structured feedback on readability, performance, and security. Use "Add logs" to inject debugging print statements. Use "Fix bugs" to target specific errors. Each action produces a new version you can roll back to. For full-screen editing, you can expand the code block to take up your entire window.

Where this shines: A backend engineer reviewing a teammate's pull request can paste the code into ChatGPT, ask for a security audit, get inline annotations on database query issues, authentication gaps, and input validation, then copy the annotated version back to GitHub. A data scientist can paste a Jupyter notebook cell and ask for optimization without rewriting the whole script. A frontend developer can paste CSS and ask for mobile responsiveness, getting the code block rewritten while the chat shows exact changes.