📝 Text Tool

Text Diff Checker

Paste two versions of any text and see exactly which lines were added, removed or kept — instantly.

Original — the older version
Changed — the newer version
Lines added0
Lines removed0
Unchanged lines0
Similarity0%
Added Removed Unchanged
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Precise LCS Diff
A real longest-common-subsequence algorithm finds the minimal set of changes — not a naive line match.
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Two Views
Inline mode shows the story top-to-bottom; side-by-side puts both versions next to each other.
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100% Private
Comparisons run locally — contracts, essays and code never leave your device.

What is a Text Diff Checker?

A diff checker compares two texts and highlights the differences: lines present only in the first version, lines added in the second, and the unchanged lines around them. ToolLove's diff uses the longest-common-subsequence algorithm — the same approach behind git diff — so the results are precise and minimal.

❓ Frequently Asked Questions

Each text is split into lines, then a longest-common-subsequence (LCS) pass finds the largest set of lines that appear in both, in order. Everything else is marked as added or removed.

Thousands of lines compare in well under a second. Extremely large files (tens of thousands of lines) may take a moment on the side-by-side view.

Lines are compared exactly, including leading and trailing spaces. Trim your input first (for example with our Text Tools) if you want a looser comparison.

No. Diffing happens entirely in your browser — nothing is sent to any server.