DiffMerge - Guide

Compare and merge directories, files, and text side by side. Visualize differences with color-coded highlights and merge in either direction.


Getting Started

  1. Set the left and right paths (browse, type, or drag and drop)
  2. Adjust comparison settings and filters as needed
  3. Click Compare to start
  4. Directories open the directory comparison view; files open the text comparison view

Or click Compare New Texts to compare two text strings directly.


Directory Comparison

Files from both directories are listed side by side with a status column in the center.

Status Colors

StatusMeaning
Left OnlyFile exists only on the left
Right OnlyFile exists only on the right
DifferentFiles differ in content/size/date
Fuzzy MatchDiffer only in whitespace
SameFiles are identical

Comparison Methods

MethodCompares
sizeFile size only
timestampModification date only
size+timestampBoth (default)
contentByte-by-byte file content

Merge Operations

  • Left → Right — copy files from left to right
  • Left ← Right — copy files from right to left
  • Delete — remove selected files
  • All merge operations support Undo / Redo

Navigation

  • Use the toolbar buttons or shortcuts to jump between differences
  • Filter by status: show/hide Left Only, Right Only, Different, Same
  • Right-click for context menu including Copy Path (filename, relative, or full path)

Text Comparison

Two editors displayed side by side with differences highlighted line by line.

  • Word-level diff highlighting (optional)
  • Fuzzy matching — ignores whitespace differences (configurable pattern)
  • Synchronized scrolling (toggleable)
  • Encoding auto-detection with manual override
  • Binary files displayed as hex dump (read-only)

Merge

  • Merge individual blocks or all differences at once
  • Bidirectional: left → right or right → left
  • Full Undo / Redo support
  • Paste text from clipboard into either side

Comparison History

  • Previous comparisons are saved and listed on the main screen
  • Double-click to re-run a comparison
  • Right-click to load settings or delete
  • Sortable by name, paths, date, and type

Keyboard Shortcuts

Directory Comparison

ActionShortcut
Next diffOption +
Previous diffOption +
First / Last diffOption + Shift + /
Merge left → rightCmd + Option +
Merge right → leftCmd + Option +
DeleteCmd + Option + Delete
Re-compareCmd + R
Undo / RedoCmd + Z / Cmd + Shift + Z

Text Comparison

ActionShortcut
Next / Previous diffOption + /
Merge selection left → rightCmd +
Merge selection right → leftCmd +
Merge all left → rightCmd + Shift +
Merge all right → leftCmd + Shift +
Re-compareCmd + R
PasteCmd + V

Tips

  • Filters — Use file/folder filters to focus on specific file types (e.g., *.py) or exclude build artifacts
  • Content comparison — Use "content" method for the most accurate comparison, at the cost of speed
  • Fuzzy matching — Great for comparing code where only indentation differs
  • Copy Path — Right-click any file in the comparison list to copy its filename, relative path, or full path

Privacy

  • All comparisons run locally on your computer
  • No file content is sent to any server
  • Comparison history is stored only on your local disk