Text Compare

What does Text Compare do?

Text Compare finds the differences between two texts word by word. It shows a single combined view in which added words are green and removed words are red with a line through them, and it reports how many words were added, removed and kept, plus an overall similarity score.

How to use it

1. Paste the original text on the left and the changed text on the right.
2. Click Compare texts.
3. Read the highlighted result below. Use Swap to reverse the comparison.

How the comparison works

• Both texts are split into words and spaces. The tool then finds the smallest set of additions and removals that turns the original into the changed text, using the Myers difference algorithm, the same approach many version-control tools use.
• A changed word is shown as the old word removed and the new word added.
• Ignore case treats “Word” and “word” as the same.
• Ignore extra spaces treats any run of spaces as one space, so formatting changes do not appear as edits.
• Similarity = 2 × unchanged words ÷ (words in both texts) × 100.

Very long texts with many changes may be too large to compare word by word in the browser. If that happens, compare one section at a time.

When to use it

• Checking what an editor or co-author changed in your draft.
• Comparing two versions of a contract clause, policy or cover letter.
• Seeing how a paraphrased passage differs from the original.
• Spotting small changes in copied text, such as a missing word.

Example

Original: “The quick brown fox jumps over the lazy dog.” Changed: “The quick red fox leaped over the lazy dog.” The result shows “brown” and “jumps” removed, and “red” and “leaped” added.