diff-viewer

April 17, 2026 ยท View on GitHub

Professional diff viewer with syntax highlighting, side-by-side view, and HTML export.

Node.js License: MIT

Quick Start

node diff_engine.js diff file1.js file2.js
node diff_engine.js sbs old.json new.json
node diff_engine.js html old.txt new.txt "v1 vs v2"
node diff_engine.js dir ./old-project ./new-project

Features

  • LCS (Longest Common Subsequence) diff algorithm
  • Syntax highlighting (20+ languages)
  • Side-by-side view
  • Word-level diff
  • HTML export (standalone, dark theme)
  • Directory comparison

HTML Export

node diff_engine.js html old.js new.js "config changes"
# Opens: diff.html

Architecture

Pure Node.js, no external dependencies.