Text Diff Checker
Compare two texts and see exactly what was added or removed.
How to use: Paste the original text and the changed text, then press Compare to see what differs.
How to use the Text Diff Checker
A diff tool shows what changed between two versions of a text. It is useful when you edit a document, review a contract revision, check a translation, or compare two versions of a configuration file.
Paste the original on the left and the changed text on the right, then press Compare. In line mode each changed line is shown with a plus (added, green) or minus (removed, red) marker, similar to what developers see in version control. In word mode the full text is shown inline with added words highlighted in green and deleted words struck through in red, which is easier for prose.
The comparison uses the longest common subsequence algorithm to find the smallest set of changes, so moved or reworded passages appear as clearly as possible. Options let you ignore differences in capitalization and in extra spaces, which helps when text has been reformatted but not rewritten.
Very large inputs are limited to keep your browser responsive; if you hit the limit, compare the text in sections. Everything runs locally, so confidential drafts are never uploaded. For code or structured data, format it first, for example with the JSON formatter, so that formatting differences do not hide the real changes.
Frequently asked questions
How does the comparison work?
It finds the longest sequence of lines or words common to both texts and marks everything else as added or removed.
Is my text uploaded?
No. The comparison happens entirely in your browser.
Is there a size limit?
Yes, very large texts are limited to keep the page responsive. Split big documents into sections if needed.