Text difference checker
See what changed between two plain-text drafts. A line-based comparison marks additions and removals and leaves the original inputs available for reference.
Text difference checker
Runs on your deviceA line is the unit of comparison
The checker treats a whole line as one unit. If one word changes in a long paragraph with no line breaks, that paragraph appears once as removed and once as added. It does not highlight individual words within the paragraph. Break a document into sensible lines if you want a more focused comparison. Differences in capitals, spaces, and punctuation count as changes.
How the comparison chooses a path
The tool finds a longest shared sequence of lines and displays the surrounding additions and removals. Repeated identical lines can produce more than one equally valid alignment. The result is a useful account of textual change, not a claim about the author’s intention. A moved line can appear as a removal in its old location and an addition in the new one.
Review content and formatting separately
The input is plain text. It cannot compare font styles, tracked comments, page layouts, or embedded images. Compare those in the original document application. The tool accepts up to 500 lines per version and 100,000 combined characters to keep the comparison responsive. Text is rendered as text rather than interpreted as HTML, so code snippets are safe to inspect here.
Worked examples
| Original | Revised | Shown change |
|---|---|---|
| Buy milk | Buy bread | One removed line; one added line |
| A then B | A then B | No differences |
Good questions.
Does it compare words?
The algorithm compares complete lines. A changed word makes its whole line different.
Why does moved text look deleted and added?
The tool preserves sequence. It does not have a separate moved-text detector.
Can I compare Word files?
Copy the text first. This tool does not read document files or compare rich formatting.
Updated 5 November 2026 · Methods & corrections