Text Diff Checker
Compare two texts and highlight differences.
100% private — runs in your browser, nothing is uploaded.
How to use the Text Diff Checker
- 1Paste the original
Put the first version of your text in the left box.
- 2Paste the changed text
Put the second version in the right box.
- 3Review the differences
Added lines appear in green and removed lines in red, with a summary count above.
Free online text diff checker
This text diff checker compares two blocks of text and highlights the differences line by line — added lines in green, removed lines in red. It is perfect for spotting changes between two versions of a document, article, config file or code snippet.
How to use it
- Paste the original version in the left box.
- Paste the updated version in the right box.
- The differences appear instantly below, with a summary count.
Everything runs locally in your browser, so your text is never uploaded.
Frequently Asked Questions
How does the diff checker work?
Paste the original text on the left and the changed text on the right. The tool compares them line by line and highlights added lines in green and removed lines in red.
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser, so even confidential documents stay private.
Can it compare code?
Yes. It works with any plain text, including source code, config files, JSON and logs, since it compares line by line.
What do the colours mean?
Green lines were added in the changed text, red lines were removed from the original, and unchanged lines are shown in grey.
Does it compare word by word or line by line?
It compares line by line using a longest-common-subsequence algorithm, which is ideal for documents, lists and code where each line is a unit.