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Text Diff

Compare two texts and highlight what was added and removed.

1 line
1 line

About this tool

Comparing two versions of a document by eye is slow and easy to get wrong. This tool aligns the two texts and marks exactly what was added and removed — line by line for edits across a file, or word by word when a single sentence changed.

Windows and Unix line endings are treated as equivalent, so pasting from different machines does not report every line as changed.

How to use it

  1. Paste the original text on the left and the changed text on the right.
  2. Choose line-by-line or word-by-word comparison.
  3. Press Compare and read the marked-up result.

Example

Original / Changed
the quick brown fox
the quick red fox
Word-by-word result
the quick -brown +red fox

FAQ

Is my text uploaded anywhere?
No. The comparison runs in your browser. Nothing is sent to a server, and this page has no analytics.
What is the difference between line and word mode?
Line mode reports whole lines as added or removed, which suits edits spread across a file. Word mode pinpoints the changed words inside a line, which suits a single edited sentence.
Does it handle Windows line endings?
Yes. CRLF and LF are normalised before comparing, so a file pasted from Windows is not reported as entirely different from the same file on macOS or Linux.
How large can the texts be?
Each side is limited to about 500,000 characters. Beyond that the comparison is refused rather than left to freeze the browser tab.
Can I compare JSON with this?
You can, but the JSON Diff tool is better for it: it compares parsed structures, so reformatting or reordering keys does not show up as a difference.