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 gives you two ways to review. On any GitHub pull request page, click the View Diff button to open a full-screen overlay with the entire change set in one scrollable view. Prefer more space or want to keep the diff open while you browse elsewhere? Open the same review in a separate browser tab, or right-click any PR link on GitHub and choose Open in diffy from the context menu. Read, navigate, and comment without jumping between files or fighting the default UI.

WHY diffy?

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 on PR pages

A View Diff button appears on every GitHub pull request. diffy prefetches PR data as the page loads, so the overlay opens quickly. No workflow change: open a PR and go.

Standalone tab experience

Detach the review into its own browser tab for more screen space, or open a PR directly in diffy via the context menu. The same full-screen diff, file tree, and review tools work in both the overlay and the tab.

Full-screen, continuous diffs

Scroll through every changed file in one view. Sticky file headers keep you oriented. Collapse or expand individual files; viewed files auto-collapse.

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 list. Comment badges mark files with open threads.

PR sidebar at a glance

See file, line, and comment stats plus branches, author, state, labels, and reviewers without leaving the diff.

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

Select lines and leave inline comments or reply to threads without leaving the viewer. Review where you read.

Batch review workflow

Queue multiple comments, then publish them in one review with Comment, Approve, or Request changes.

Viewed-file tracking

Mark files as viewed, track progress (e.g. 3/12 viewed), and jump to the next unviewed file.

Split or unified layout

Switch between side-by-side and stacked diff views. Tune display settings: diff indicators, hunk separators, line numbers, and wrap vs horizontal scroll.

Syntax highlighting for 100+ languages

Clear, colorized diffs from TypeScript and Python to Dockerfiles, SQL, and more.

50+ themes

Auto, light, and dark mode with separate theme picks: Pierre, GitHub, Catppuccin, Dracula, Nord, Tokyo Night, Everforest, One Dark Pro, and more.

Fast and responsive

Opens quickly, prefetches in the background, and stays smooth where GitHub's tab can lag. Your layout, display, and theme preferences are remembered.

Private repository support

Add an optional GitHub personal access token in the extension popup for private repos, higher API rate limits, posting comments, viewed-file tracking, and batch reviews.

diffy works on public repositories out of the box. A token is only needed for private repo access, higher API limits, or the full review workflow (comments, viewed files, and publishing reviews).

Under 2 MB

Lightweight install despite 100+ languages, 50+ themes, and full PR rendering.

Powered by Pierre

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

Open source

Report issues, request features, or contribute on GitHub:

https://github.com/suveshmoza/diffy