Text & Code Diff Checker
Find the differences between two versions of a text, config or code file. Changed lines are paired and the changed words highlighted.
Original
Changed
Paste two versions to see the differences.
How to use it
- 1Paste the original on the left and the changed version on the right, or open files.
- 2Choose side-by-side or inline view; tick "Ignore whitespace" or "Ignore case" if those changes don’t matter.
- 3Scroll the result: removed lines are red, added lines green, changed words stand out within a line.
Private by design
Everything runs in this browser tab. Your input is never uploaded, logged or saved on a server, and there are no public "recent" pages. Close the tab and it's gone.
How we keep it privateExamples
Only "process.env.PORT ??" is highlighted inside the line.
Input
Original: const PORT = 3000; Changed: const PORT = process.env.PORT ?? 3000;
Output
- const PORT = 3000; + const PORT = process.env.PORT ?? 3000;
Options explained
- Ignore whitespace: lines that differ only in spaces, tabs or indentation count as equal. Useful after reformatting.
- Ignore case: "Error" and "error" count as equal.
- Unchanged stretches are folded to a few lines of context; use "Show all lines" to expand them.
- Windows (CRLF) and Unix (LF) line endings are treated the same.
Comparing JSON?
Use the JSON Compare tool instead: it ignores key order and formatting and lists each change with its path, which a line diff can’t do.
Frequently asked questions
Is my text uploaded or saved?
No. The comparison runs in a background thread of this page. Nothing is sent to a server, there are no saved diffs and no public links, so contracts, configs and code stay private.
How big can the texts be?
Several megabytes each. The diff runs off the main thread, and very long results are shown up to a limit with the totals kept exact.
What algorithm is used?
A line diff based on the Myers algorithm (the same idea as git diff), followed by a word diff on each changed line pair.