Text Diff Checker

Compare two blocks of text and see line-by-line differences, added and removed lines highlighted.

Diff (line-based)

How this diff works
This tool performs a line-by-line longest-common-subsequence diff, similar to diffon the command line. Lines only in the original are marked with - and shown in red; lines only in the changed text are marked with + and shown in green.
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About Text Diff Checker
Text Diff Checker compares two blocks of text line by line or word by word to highlight additions, removals, and changes.
How to use Text Diff Checker
  1. Paste original text into the left pane.
  2. Paste revised text into the right pane.
  3. Select comparison granularity (line diff or word diff).
  4. Click Compare Text to view color-coded diff output.
Examples
Original: The quick brown fox
Revised: The fast brown fox
Diff: "quick" removed, "fast" added.
FAQ
Can I toggle whitespace sensitivity during comparison?
Yes. You can choose to ignore leading and trailing whitespace changes when computing text diffs.
Is diff comparison executed locally?
Yes. Diff calculations run entirely within browser memory.
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