Compare two plain text documents side by side with visual highlighting of differences. This tool helps you identify changes between text files, analyze document variations, and review modifications. Choose between line-by-line or word-by-word comparison modes for different levels of detail. The side-by-side view shows original text on the left and modified text on the right with color-coded differences. Use the "Normalize Whitespace" option to ignore spacing differences and remove empty lines for cleaner comparisons. All processing happens locally in your browser for maximum privacy and security.