Text Diff Checker
Line and word diff with add/remove highlighting.
Added
–
Removed
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Unchanged
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Diff
How it works
Text is tokenised (into words or lines) and compared with a classic
longest common subsequence (LCS) diff, the same technique behind diff
and Git's line-level diff. Matched tokens are shown as-is, removed tokens are
struck through in red, added tokens are highlighted in green. Everything runs
locally in your browser.
Very large inputs (roughly 20,000+ characters) are rejected to keep the comparison fast, since LCS diffing is O(n×m).