Compare API responses and JSON payloads without leaving VS Code — structural key-level JSON diff, git histogram algorithm, any file size.
Why Diffmin
The workflow every backend developer knows:
Get an API response → open a browser tab → paste → switch back to VS Code
→ copy second response → switch back → paste → compare → switch back again.
Diffmin kills this entirely:
Ctrl+Shift+P → Diffmin: Open Diff Panel → paste both → done.
Everything runs locally. Nothing leaves your machine.
Features
Two diff engines
JSON structural mode — key-level comparison that understands your data. Shows address.city: "New York" → "San Francisco" instead of 40 lines of red/green noise.
Text mode — uses git diff --histogram (git's own recommended algorithm) for semantically meaningful hunks. Falls back to Myers diff if git is not installed.
Works on any file size
Virtual scrolling renders only the visible rows — 500k-line files open instantly, scroll smoothly, never freeze.
Tight VS Code integration
Compare two files — select any two files in Explorer → right-click → Diffmin: Compare Selected Files
.json files → structural diff in Diffmin
Everything else → VS Code's native diff editor
Diff with HEAD — right-click a file → Diffmin: Diff with HEAD
.json files → structural diff (HEAD vs working tree)
Everything else → VS Code's native git diff
Diff view features
Feature
Description
Word highlights
Changed words within a line are highlighted
Fold unchanged
Unchanged regions collapse to save space
Jump nav ↑↓
Jump between change hunks
Changes only
Hide unchanged lines entirely
In-diff search
Ctrl/Cmd+F searches across the diff
Ignore whitespace
Toggle whitespace-blind comparison
Sort JSON keys
Normalise key order before diffing
Format JSON
Pretty-print minified JSON before diffing
Swap sides
Flip left ↔ right
Paste / Copy
Clipboard buttons on each pane
Usage
Open the diff panel (manual paste)
Ctrl+Shift+P → Diffmin: Open Diff Panel
Paste or type content into both panes
Click Compare
Compare two files from Explorer
Hold Ctrl (or Cmd on Mac) and click two files in the Explorer sidebar
Right-click → Diffmin: Compare Selected Files
Diff a file against git HEAD
Right-click any file in Explorer → Diffmin: Diff with HEAD
— or right-click the editor tab title
Commands
Command
Description
Diffmin: Open Diff Panel
Open the manual paste panel
Diffmin: Compare Selected Files
Diff two Explorer-selected files
Diffmin: Diff with HEAD
Diff a file against its git HEAD version
Requirements
VS Code ^1.85.0
Git (optional — used for --histogram algorithm and Diff with HEAD; falls back gracefully if not installed)
