diffy

About

Review pull requests the way they should feel: one continuous, full-screen diff with a searchable file tree, inline comments, and fast rendering — even on the PRs where GitHub’s Files changed tab starts to struggle.

diffy adds a "View Diff" button to every GitHub pull request. Click it to open a dedicated overlay that loads the entire change set in one scrollable view, so you can read, navigate, and comment without jumping between files or fighting the default UI.

GitHub’s Files changed tab works well for everyday reviews. On bigger pull requests - hundreds of files, large patches, or heavy review threads - you often run into friction:

Diff too large to display - GitHub caps total PR diffs and refuses to render beyond certain limits  
300+ changed files - the unified diff endpoint can fail; GitHub tells you to use the files API instead  
Load diff” on every large file - only the first chunk loads automatically; you click through file by file  
File-by-file navigation - easy to lose context across a big change set  
Sluggish UI -  reviewers report lag, high memory use, and freezes on medium-to-large PRs  
Scattered comments - threads split across Conversation and Files changed are hard to track

diffy addresses these by fetching changes through the GitHub API and rendering them in a lightweight, purpose-built viewer -bypassing GitHub’s web UI diff renderer where it falls short.

**What you get**

One-click access: A **View Diff** button appears on GitHub pull request pages. No workflow change, open a PR and go.

Full-screen, continuous diffs: Scroll through every changed file in one view. Sticky file headers keep you oriented as you move through the PR.

Searchable file tree: Jump to any file instantly, even in PRs with hundreds of changes. Search filters the tree so you never hunt through a long file list.

Inline review comments: Read existing review threads directly on the lines you’re looking at. Unresolved discussions stay visible in context.

Comment from the diff: Leave inline comments and reply to threads without leaving the viewer. Review where you read.

Split or unified layout: Switch between side-by-side and stacked diff views to match how you prefer to review.

Syntax highlighting for 100+ languages: Clear, colorized diffs from TypeScript and Python to Dockerfiles, SQL, and more.

12 themes: Choose the look that fits your setup: Pierre dark/light, GitHub, Catppuccin, Dracula, Nord, Tokyo Night, Everforest, One Dark Pro, and more.

Fast and responsive: Opens quickly, prefetches data in the background, and stays smooth where GitHub’s tab can lag. Your layout and theme preferences are remembered.

Private repository support: Optionally add a GitHub personal access token in the extension popup for private repos, higher API rate limits, and posting comments.

diffy works on public repositories out of the box. A token is only needed when you want private repo access, higher API limits, or the ability to post review comments.

Powered by Pierre

diffy is built with [Pierre Trees](https://trees.software) and [Pierre Diffs](https://diffs.com)

diffy is open source. Report issues, request features, or contribute on GitHub:  
https://github.com/suveshmoza/diffy