diffy

The missing PR review experience on GitHub

Full-screen diffs, searchable file tree, inline comments, split/unified layout, 100+ languages, and 12 themes.

Install diffyExplore features

Built using Pierre FileTree and CodeView

Why diffy

GitHub's Files changed tab breaks down on big PRs

Hundreds of files, large diffs, and heavy review threads hit documented limits and long-standing UX friction. diffy is built for exactly those reviews.

1

Diff too large to display

GitHub caps total PR diffs at 20,000 lines / 1 MB and refuses to render beyond that.

Fetches changes through the GitHub API and renders them in a dedicated viewer.

2

300+ changed files

The unified diff endpoint returns a 406 error. GitHub tells you to use the files API instead.

Uses the paginated files API to load every changed file, then assembles the full diff.

3

Load diff on every large file

GitHub only auto-loads the first 400 lines / 20 KB per file. You click to load the rest one file at a time.

Shows full file patches in one continuous scroll. No per-file load buttons.

4

File-by-file review

Expand, collapse, and jump between files. Easy to lose context across a big PR.

One continuous full-PR view with a searchable file tree to jump anywhere instantly.

5

Slow Files changed tab

Reviewers report UI lag, high memory use, and multi-second freezes even on medium PRs.

A lightweight overlay with fast rendering. Stays responsive where GitHub's tab struggles.

6

Comments scattered across tabs

Unresolved threads are hard to track in Conversation vs Files changed.

Inline review comment threads rendered directly on the lines you are reading.

Features

Everything ships in the extension today. Powered by FileTree and CodeView.

One-click access

A View Diff button on every GitHub pull request. No copy-pasting URLs.

Full-screen diffs

Scroll through the entire PR in one continuous view.

Fast and smooth

Opens quickly and remembers where you left off between sessions.

File tree with search

Jump to any changed file, even in huge PRs. Filter as you type.

Review comments inline

Read existing threads right in the diff, on the lines you are reviewing.

Comment from the diff

Leave inline comments and reply without leaving the viewer.

Split or unified layout

Switch between side-by-side and stacked views in one click.

Syntax highlighting and 12 themes

100+ languages with sticky file headers, plus Pierre dark/light, GitHub, Catppuccin, Dracula, Nord, Tokyo Night, and more.

Private repo support

Add a GitHub token in the extension popup when you need private repo access.

How it works

Four steps from any pull request to a faster review.

  1. 1

    Open any GitHub PR

    diffy adds a View Diff button to the page when you land on a pull request.

  2. 2

    Open the full-screen viewer

    Click View Diff to see every changed file in one scrollable overlay.

  3. 3

    Search and jump files

    Use the file tree on the left to filter and jump between files instantly.

  4. 4

    Read and leave comments

    Review threads appear inline. Reply and comment without leaving the diff.

See it in action

Explore the panels that power the overlay.

File tree and search

Hierarchical tree with M/A badges and per-file +/− counts.

Inline review comments

Line 21

suveshmoza1m ago
EditDelete

Parent Comment

suveshmoza1m ago
EditDelete

Nested Comment

suveshmoza1m ago
EditDelete
Nested Comment

Quoted Comment

Threaded replies with quote reply, edit, delete, and GitHub link actions on each comment.

Layout toggle

assets/pierre-github.css-1 +142
17 unmodified lines
19.diffy-overlay-toolbar {
20 display: flex;
21 flex-direction: row;
19.diffy-overlay-toolbar {
20 display: flex;
21 flex-direction: column;
2 unmodified lines
24}
24}

Side-by-side for comparing hunks, unified for reading top to bottom.

Theme picker

12 syntax themes. The whole page updates live.

Install diffy

Coming soon to browser extension stores. Install from source on GitHub in the meantime.

Chrome

Coming soon

Firefox

Coming soon

Edge

Coming soon

Privacy and trust

Your code and data stay yours. No hidden trackers, no surprises.

No data collection

diffy does not collect any personal data. No tracking, no telemetry, no analytics.

Optional GitHub token

Only needed for private repositories and posting review comments. Stored locally in your browser.

Open source

The entire source code is available on GitHub. Anyone can read it, build it, or contribute.