Text Diff
Spot every change instantly. Paste two texts, see additions in green and deletions in red.
How the Text Diff Tool Works
Paste your original text in the first box and your modified text in the second. The tool compares both versions line by line using the Longest Common Subsequence (LCS) algorithm — the same method used by Git and professional diff tools.
Green lines (marked with +) are additions in the modified text. Red lines (marked with −) are deletions from the original. Switch between Inline and Side-by-side views depending on your preference.
Frequently Asked Questions
What algorithm does this diff tool use?
The tool uses the Longest Common Subsequence (LCS) algorithm, which finds the largest set of lines that appear in both texts in the same order. This produces minimal, human-readable diffs — the same approach used by Git.
Is my text sent to any server?
No. All comparison happens entirely in your browser using JavaScript. Nothing is sent to any server. Your text never leaves your device.
Can I compare code files?
Yes. The diff tool works on any plain text — code, prose, configuration files, CSV data. Paste any text you want to compare. The monospace font makes code diffs easy to read.
What does the Swap button do?
Swap exchanges the original and modified texts, effectively reversing the diff direction. Additions become deletions and vice versa. Useful when you want to see the changes from the opposite perspective.
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