Diff Checker
Compare two texts and see what changed — in your browser
About Diff Checker
Compare two blocks of text and instantly see which lines were added or removed. A fast, private, browser-based diff tool.
How to use the diff checker
- Paste the original text on the left.
- Paste the changed text on the right.
- Added and removed lines are highlighted.
- Nothing is uploaded — it all runs locally.
Frequently asked questions
Does it compare line by line?
Yes, it performs a line-based diff and marks added and removed lines, with a count of each.
Are my files uploaded to a server?
No. Everything runs locally in your browser using JavaScript, so your files and text never leave your device.
Is this tool free?
Yes, it is completely free with no signup, no watermarks and no limits.