seamdiff
A beautiful, distraction-free diff viewer for macOS. Compare any two files side by side with the power of a native app, dark mode, and instant feedback.
macOS 13+ · $9.99 · No subscription
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.
Folder diff
Compare entire directories. Navigate changed files and filter by modified, added, or removed at a glance.
Drag & drop
Drop any file or folder directly onto the window — no file picker, no clicks.
What's coming
Roadmap
Growing fast. Here's what's shipped and what's next.
v0.1 — Core diff viewer
Side-by-side and inline diff, dark & light mode, Monaco editor, customizable colors, live change stats.
v0.3 — Folder diff & drag and drop
Compare entire directories, navigate changed files, filter by modified/added/removed — and drop files straight onto the window.
v0.4 — Visual diff gutter
Bezier connector bridges show how every changed block maps between the two files. Line numbers move into the gutter, highlighted for changed lines.
v0.5 — Merge & save
Click ← or → on any diff block to copy it across. Undo, then save the result back to disk — a full merge workflow without leaving the app.
Git integration
Open a repo and diff any two commits, branches, or the working tree — right inside SeamDiff.
Clipboard diff
Paste text directly into either panel without needing a file on disk.