WhatTheDiff automates the most tedious part of the code review process — understanding what a pull request actually does. The tool analyzes git diffs using AI to generate plain-language summaries that explain not just what changed but the intent behind the changes. Reviewers can quickly grasp the scope and purpose of a PR without reading every line of code, significantly reducing review time for large or complex changes.
Beyond summarization, WhatTheDiff offers code refactoring suggestions that identify opportunities for simplification, performance improvement, and better practices. The /wtd command in PR comments triggers on-demand analysis of specific sections. The tool integrates with GitHub through a GitHub App, automatically generating summaries when PRs are opened or updated. Teams can customize the level of detail and focus areas for summaries to match their review workflow.
WhatTheDiff operates on a freemium model with a free tier for individual developers and paid plans for teams needing higher volume and advanced features. For engineering teams where PR review bottlenecks slow down development velocity, WhatTheDiff provides the AI assistance that keeps reviews flowing without sacrificing thoroughness. The generated summaries also serve as documentation, making it easier to trace changes during debugging and compliance audits.