Original (A)
Changed (B)
Diff Result
How it works
The Text Diff Checker compares two blocks of text and highlights the differences between them — showing added characters or lines in green, removed content in red, and unchanged text in gray. It operates at both the line level and the character level.
Diff comparison is fundamental in software development (git diff), document collaboration (tracking changes), content publishing (comparing drafts), and data processing (verifying transformation outputs). This browser-based diff tool handles all these cases without exposing your content to a server.
How to use it: paste the original text in the left panel and the modified text in the right panel. The diff appears below, showing additions and deletions highlighted. Toggle between "Line diff" (compares whole lines) and "Word diff" (highlights specific changed words) and "Character diff" (shows individual character changes).
Use cases: comparing two versions of a contract or legal document, verifying that a text transformation produced the expected output, reviewing changes to a configuration file, comparing translated text to the source for accuracy, finding the difference between two similar SQL queries, and auditing content changes before publishing.
Privacy: document content, legal text, and draft copy that you're comparing should not be sent to an external server for diffing. This tool runs the entire comparison client-side using the Myers diff algorithm — no content leaves your browser.
Frequently Asked Questions
- The Myers diff algorithm — the same algorithm used by Git for generating diffs. It finds the shortest edit script (minimum number of insertions and deletions) to transform one text into the other.
- Yes. The diff viewer handles any text content including code. Syntax highlighting is applied to the diff output when the language is detected.
- Line diff marks entire lines as added or deleted. Word diff shows changes within lines, highlighting specific added or deleted words. Character diff is the most granular — individual character changes are highlighted.
- Yes. Both text blocks are processed entirely in your browser using a JavaScript implementation of the Myers algorithm. No content is sent to a server.