Paste two pieces of text and instantly see what changed. Perfect for code reviews, document comparison, and debugging.
🔒 Your text stays in your browser. Nothing is uploaded or stored.
A diff checker (also called a difference checker or file comparison tool) compares two text files or code snippets and highlights the differences between them. It shows added lines, removed lines, and modified content in an easy-to-read side-by-side format, making it simple to see exactly what changed.
Diff checkers are essential for code reviews, debugging, document comparison, and version control. They help developers understand changes between file versions, review pull requests, merge conflicts, and track modifications in configuration files or documentation.
This diff checker runs entirely in your browser using JavaScript. Your files never leave your device or get sent to any server, making it completely safe for proprietary code, sensitive documents, or confidential data.
Compare code changes before and after modifications. Perfect for reviewing pull requests, understanding refactoring, or validating bug fixes.
Compare different versions of documents, contracts, or text files to see what changed between drafts or revisions.
Compare configuration files (JSON, YAML, XML, ENV) to identify changes in settings, environment variables, or deployment configs.
Compare API responses from different environments (dev vs prod) or different versions to spot discrepancies in data structure or values.
Compare log files from different time periods or servers to identify changes in behavior, errors, or system state.
Compare JSON files or API payloads to see structural differences, added/removed fields, or changed values in complex nested objects.
Paste the original text in the left pane and the modified text in the right pane. You can paste code, documents, JSON, or any text-based content.
Click the Compare button to analyze the differences. The tool will highlight added (green), removed (red), and modified (yellow) lines.
Scroll through the side-by-side comparison to see exactly what changed. The diff stats show the total number of additions, deletions, and modifications.
Click Copy Result to copy the comparison or Download to save it as a file for documentation or sharing.
A diff checker (difference checker) is a tool that compares two text files or code snippets and highlights the differences between them. It shows added lines, removed lines, and modified content in an easy-to-read side-by-side format.
You can compare any text-based files including source code (JavaScript, Python, Java, C++, etc.), configuration files (JSON, YAML, XML, ENV), markdown, plain text, CSV, SQL, and more. Binary files are not supported.
Yes, absolutely safe. This diff checker runs 100% in your browser using JavaScript. Your files never leave your computer or get sent to any server. Everything is processed locally on your device, making it safe for proprietary code and sensitive documents.
Yes, this tool can handle files up to several megabytes in size. Since it runs in your browser, the limit depends on your device's memory. For extremely large files (10MB+), you may experience slower performance.
Added lines (green) exist in the modified file but not in the original. Removed lines (red) exist in the original but not in the modified file. Modified lines (yellow) exist in both but with different content.