Diff Checker
Compare two texts side by side. Highlight added, removed, and unchanged lines.
How to use Diff Checker
- 1
Paste Original Text
Paste the original text or code in the left input area.
- 2
Paste Modified Text
Paste the modified version in the right input area.
- 3
Review Differences
See added lines in green, removed lines in red, and unchanged lines in default styling.
- 4
Copy as Patch
Export the diff in unified format suitable for patch files.
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Frequently Asked Questions
How does the diff algorithm work?
We use the Longest Common Subsequence (LCS) algorithm to find the minimal set of changes needed to transform one text into another.
What's the difference between Split and Unified view?
Split shows two columns (original vs modified). Unified shows one column with + and - prefixes indicating additions and deletions.
What is the similarity percentage?
It shows what percentage of lines are identical between the two texts. 100% means they're identical (ignoring whitespace if that option is on).
Can I use this for code review?
Yes! This is great for comparing code versions, checking configuration changes, or reviewing document edits.
What format is the patch export?
The patch uses unified diff format with + for added lines and - for removed lines, compatible with standard patch tools.