How to use it
- Paste the original text on the left and the changed text on the right.
- The differences appear below at once. Swap exchanges the two texts.
- Turn on “Ignore case” or “Ignore extra spaces” to hide changes that do not matter.
How it works
Both texts are split into lines. The tool looks for the longest run of lines the two texts share in order, and everything else is a change - a line only in the original was removed, a line only in the new text was added. Common lines at the start and end are matched first, so a small edit in a long document is found quickly.
Inside a block of changes, the first removed line is paired with the first added line, the second with the second, and so on. Each pair is compared again word by word, and only the words that differ are highlighted. A whole new paragraph has no pair, so it is shown simply as added.
Worked example
In the sample, line 2 changed from “on Monday at 10:00” to “on Tuesday at 11:00”, and the line “Lunch is provided.” was added. The result shows 2 added lines, 1 removed and 3 unchanged: line 2 appears as removed and added, with “Monday” and “10” marked in the old version and “Tuesday” and “11” in the new one.
Tips
Changes are shown by lines, so a paragraph written as one long line is reported as one changed line; the word highlighting still shows what changed inside it. For code and JSON, format both versions the same way first, or every line with different indentation counts as changed.