πŸ“Š Diff Checker - Text Comparison

Updated: 2026-07-11
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πŸ“ Enter the texts to compare

πŸ“– How to Use

This diff checker helps you quickly find the differences between two texts. Paste the original text into the left text area and the modified text into the right text area, then click the "Compare" button to see the result. Green highlighting shows added content, red highlighting shows deleted content, and the default style shows unchanged content.

You can also use the "Ignore Case" and "Ignore Whitespace" options to control the comparison more precisely. The "Load Example" button provides a code sample so you can try the feature. The result supports one-click copy for archiving and sharing.

⚑ Technical Principle

This tool uses the Myers diff algorithm based on the longest common subsequence (LCS) to compare texts line by line. The algorithm efficiently finds the longest common subsequence of the two texts and marks added and deleted lines accordingly. It runs in O(ND) time, where N is the number of text lines and D is the number of differences, which suits most text comparison scenarios.

πŸ’Ό Use Cases

This diff checker is useful in many scenarios: comparing different versions of code files during code review; checking the before and after of edits when proofreading articles; analyzing configuration file version changes; comparing revisions of contracts or documents; and quickly understanding what teammates changed in collaborative projects.

❓ FAQ

Does the diff checker upload my text to a server?
No. All comparison runs entirely in your browser. Your input text is never uploaded to any server, fully protecting your privacy.
How large a text can I compare?
We recommend each text under 100,000 characters. Very large texts may affect browser performance; processing speed depends on your device.
How do I read the diff result?
Green highlighting shows added content, red highlighting shows deleted content, and the default style shows unchanged text.

πŸ”— Recommended Tools

πŸ”’Character CounterCount characters and words πŸ“Text FormatterFormat and beautify text πŸ”€Case ConverterConvert text case πŸ”§JSON FormatterFormat and validate JSON πŸ“HTML FormatterFormat and beautify HTML
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