Compare two texts and highlight the differences line by line
Format, validate, and minify JSON data with syntax highlighting
Format and beautify SQL queries
Minify or beautify CSS code to reduce file size or improve readability
Write Markdown and see real-time HTML preview
Diff Checker is a free online tool that compares two blocks of text and highlights the differences between them. It displays results in a unified diff view, showing added lines in green, removed lines in red, and unchanged lines in their original state. This tool is invaluable for developers comparing code versions, writers tracking document changes, and anyone who needs to quickly spot differences between two texts. The tool shows statistics including the number of added, removed, and unchanged lines. All comparison is performed in your browser — no data is sent to any server.