Text Diff

Comparing two versions of text is one of the most common tasks in writing, editing, and software development. Whether you are reviewing changes to a contract, checking edits on a blog post, or comparing configuration files, manually spotting every difference is slow and error-prone. This text diff tool automates the process by analyzing both inputs line by line and clearly highlighting what was added, removed, or left unchanged.

The tool uses a longest common subsequence algorithm to produce an accurate and minimal diff. Added lines are highlighted in green, removed lines in red, and unchanged lines remain on a white background. Each line shows its original and modified line numbers for easy reference. A summary at the top gives you a quick count of additions, deletions, and unchanged lines so you can gauge the scope of changes at a glance.

This diff tool runs entirely in your browser, meaning your text is never sent to a server. This makes it suitable for comparing sensitive documents, private code, or confidential business content. Paste your original text on the left and the modified version on the right, click Compare, and instantly see a clean, color-coded breakdown of every difference. Use it for proofreading, code review, document versioning, or any scenario where you need to spot changes quickly.