Diff Checker
Compare Text & Find Differences
Paste two versions of text and instantly see the differences highlighted. Additions are shown in green, deletions in red. Perfect for comparing code, documents, and more.
No differences found — the texts are identical.
Line-by-Line Comparison
See exactly which lines were added, removed, or changed between two versions of text.
Color-Coded Output
Green highlights for additions and red highlights for deletions make changes immediately visible at a glance.
Code & Text Support
Works perfectly with code, configuration files, documents, and any plain text format.
100% Private
All comparison happens in your browser. Your text is never sent to any server.
Why Use a Diff Checker?
A diff (short for 'difference') tool compares two pieces of text and shows exactly what changed between them. Originally created for software development (the Unix 'diff' command dates back to the 1970s), diff tools are now essential for anyone who works with text — writers comparing drafts, developers reviewing code changes, and editors tracking document revisions.
How Does Diff Checking Work?
Our diff checker uses a line-by-line comparison algorithm. It identifies the longest common subsequence between the two texts, then highlights lines that were added (only in the modified version), removed (only in the original), or unchanged (present in both). This gives you a clear visual representation of every change, no matter how small.
Common Use Cases
Developers use diff tools daily to review code changes, compare configuration files, and debug issues between versions. Writers compare document drafts to track revisions. System administrators compare server configurations. Students verify their work against reference solutions. If you've ever needed to answer 'what changed?' — a diff checker is your answer.