Text Diff
Text diff comparison shows exactly what changed between two versions of any text — added, removed, or modified lines. Our diff tool uses the Myers diff algorithm (the same algorithm used by Git) to produce the most human-readable change set, with side-by-side and unified view modes, word-level and character-level diffing for fine-grained comparison.
Original Text
Modified Text
Line-by-Line Diff
About the Text Diff Checker
Text diff comparison shows exactly what changed between two versions of any text — added, removed, or modified lines. Our diff tool uses the Myers diff algorithm (the same algorithm used by Git) to produce the most human-readable change set, with side-by-side and unified view modes, word-level and character-level diffing for fine-grained comparison.
How to use it
- Paste the original text in the left panel and the modified text in the right panel.
- See additions highlighted in green, removals in red.
- Toggle between line diff (default), word diff, and character diff.
- Switch between side-by-side and unified (Git-style) views.
Formula & methodology
Myers diff algorithm: finds the shortest edit script (minimum additions + deletions) to transform one text into another. O(ND) time complexity where N is total lines and D is number of differences. Longest Common Subsequence (LCS) is the mathematical foundation. Similar to GNU diff and git diff output.
Common use cases
- Comparing two versions of a document or contract
- Code review: quickly visualizing changes outside an IDE
- Detecting plagiarism or unauthorized modifications to agreements
- CMS: comparing draft vs published versions
- Data validation: comparing expected vs actual output in testing
Frequently asked questions
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