Free · No signup · Runs entirely in your browser
Text Diff Checker
Paste the original and changed text below and see every added and removed line highlighted. Everything is compared locally in your browser — nothing is sent anywhere.
How it works
- Paste the original text on the left and the changed text on the right.
- The diff updates live, with added and removed lines highlighted.
- Toggle ignore whitespace or ignore case if formatting shouldn't count as a change.
- Check the added/removed counts to see the size of the change at a glance.
Frequently asked questions
What does a text diff show?
A diff lines up two versions of a text and highlights what changed — lines only in the original are marked removed, lines only in the changed version are marked added, and everything else is shown as unchanged.
Is this a line diff or a character diff?
This tool compares line by line, not character by character. A line counts as changed if any part of it differs, and it's shown as a removed line followed by an added line rather than an in-line highlight.
Is my text uploaded anywhere?
No. Both texts are compared entirely locally in your browser using JavaScript — nothing you paste is sent to a server.
What do ignore whitespace and ignore case do?
Ignore whitespace treats lines that only differ in spacing as equal, and ignore case treats lines that only differ in letter case as equal. Both only affect how lines are compared — the original text is still shown in the results.
Can I diff code with this?
Yes. It works on any plain text, including source code, config files, or logs — paste the before and after versions and the changed lines are highlighted.