Diff Checker
Compare two texts side by side with line-by-line diff highlighting. See added, removed, and changed lines instantly — no server, no signup.
Frequently Asked Questions
How is the diff calculated?
The diff uses the Longest Common Subsequence (LCS) algorithm, the same method used by tools like Git and Unix diff. It finds the longest sequence of lines that appear in both texts unchanged, then marks everything else as added or removed.
How is this different from a version control diff?
A version control diff (like git diff) operates on files stored in a repository and tracks history. This tool works on arbitrary text you paste in, making it quick for one-off comparisons without needing a repo. The underlying algorithm is the same.
What are the best use cases for a diff checker?
Common uses include comparing two versions of a document before and after editing, checking configuration files for differences, reviewing contract or legal text changes, comparing code snippets outside of a version control system, and verifying that a copy-paste operation did not introduce changes.