How to read the result

Paste the old version on the left and the new one on the right. Lines that are only in the original are shown in red with a minus, lines only in the new version are green with a plus, and unchanged lines are plain. When one line was edited rather than replaced, the words inside it that changed are highlighted, so a one-word fix doesn’t hide in a long line. The two small number columns are the line numbers in each version.

Ignore case and Ignore extra spaces treat lines as equal when they only differ in capital letters or in the amount of white space, which helps with copied text and code that was re-indented. Show only changes folds long stretches of unchanged lines.

Questions

Is my text uploaded? No. The comparison runs in your browser, and nothing you paste is saved.

How big can the texts be? A few thousand lines each when they are similar. If two long texts are almost entirely different, the tool says so rather than slowing your browser down; compare smaller sections.

Can it compare files? Open the file in any editor, copy its contents and paste them in. To count words in either version, use the Word Counter.