seamdiff

A beautiful, distraction-free diff viewer for macOS. Compare any two files side by side with the power of native app, dark mode, and instant feedback.

1function greet(name) {

2 console.log('Hello, ' + name)

5const users = [

6 'Alice',

7 'Bob',

10users.forEach(greet)

12module.exports = { greet }

1function greet(name) {

2 console.log(`Hello, ${name}!`)

5const users = [

6 'Alice',

7 'Bob',

8 'Carol',

11users.forEach(greet)

13export default greet

Why SeamDiff

Everything you need, nothing you don't

Side-by-side or inline

Toggle between split view and unified diff — whatever fits your workflow and screen.

Dark & light mode

Follows your system preference automatically, or lock it to dark or light — your call.

Monaco editor power

Built on the same engine as VS Code — syntax highlighting, minimap, font controls, and more.

Customizable colors

Tune the highlight colors for added and removed lines — opacity, hue, everything.

Any file type

Open any two text files and diff them instantly. No project setup, no configuration files.

Live diff stats

Instant count of changes, additions, and removals shown in the footer as you work.

Setup steps

∞

File types supported

macOS

Native app

What's coming

Roadmap

SeamDiff just launched. Here's where it's headed.

Shipped

v1.0 — Core diff viewer

Side-by-side and inline diff, dark & light mode, Monaco editor, customizable colors, live change stats.

Up next

Folder diff

Compare entire directories, navigate changed files with a tree view, and spot what's been added, removed, or modified at a glance.

Planned

Drag & drop

Drop files directly onto the window to open them — no file picker needed.

Planned

Git integration

Open a repo and diff any two commits, branches, or the working tree — right inside SeamDiff.

Planned

Clipboard diff

Paste text directly into either panel without needing a file on disk.