Compare two texts and find every difference instantly. Character-level highlighting, file upload, side-by-side view — all free, all in your browser.
This tool uses a line-by-line comparison algorithm similar to what Git uses internally. It identifies which lines were added, removed, or modified between the two texts. For modified lines, it runs a second character-level pass to highlight the exact characters that changed within each line.
Yes. This diff checker works with any text format including source code in JavaScript, Python, HTML, CSS, JSON, XML, SQL, and any other programming language. It preserves formatting, indentation, and special characters. It is ideal for code reviews, comparing different versions of a file, or debugging configuration changes.
All comparisons happen entirely in your browser using JavaScript. Your text is never sent to any server. No data is stored, logged, or transmitted. The tool works even when you are offline after the page has loaded.
Line-level diff shows which entire lines were added, removed, or changed. Character-level diff goes further — within changed lines, it highlights the specific characters that differ. Character-level is more useful for catching small typos, variable name changes, or minor edits within long lines.
This tool handles files up to 50,000 lines per side efficiently. For very large files (100,000+ lines), performance may slow due to browser memory limitations. For such cases, use a desktop tool like VS Code's built-in diff viewer or the command-line diff utility.
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