Compare two texts side by side and find the differences. Highlight additions, deletions, and changes with our free online diff tool.
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Why use a Diff Checker?
A diff checker is an essential tool for comparing two versions of text to identify what has changed. Whether you're reviewing code changes, comparing document revisions, checking contract modifications, or verifying content updates, our diff tool makes it easy to spot every addition, deletion, and modification. The color-coded highlighting ensures you never miss a change, while the flexible comparison modes (characters, words, or lines) let you analyze changes at the granularity you need.
Frequently Asked Questions
How does the diff checker work?
Our diff checker uses the Longest Common Subsequence (LCS) algorithm to compare two texts and identify the differences. It breaks down the text into segments based on your chosen comparison mode (characters, words, or lines), then highlights what was added, removed, or kept the same. Green highlighting shows additions, red shows deletions, and unmarked text remains unchanged.
What's the difference between character, word, and line comparison?
Character comparison analyzes every single character, making it ideal for spotting typos or minor edits. Word comparison treats each word as a unit, perfect for document revisions and content changes. Line comparison is best for code reviews and structured documents where changes typically happen line by line. Choose based on what level of detail you need.
Can I compare files directly?
Yes! You can upload text files (.txt, .md, .json, .xml, .html, .css, .js, .ts) directly using the upload button above each text area. The file content will be loaded automatically for comparison. This is especially useful for comparing code files or configuration files.
What do 'Ignore case' and 'Ignore whitespace' options do?
The 'Ignore case' option treats uppercase and lowercase letters as identical, so 'Hello' and 'hello' would be considered the same. 'Ignore whitespace' normalizes all whitespace (spaces, tabs, multiple spaces) to single spaces, useful when formatting changes but content remains the same. These options help you focus on meaningful differences.
Is my text data secure?
Yes, absolutely! All text comparison happens entirely in your browser using JavaScript. Your text is never uploaded to any server, making it completely private and secure. You can use this tool with sensitive documents, code, or confidential content without any privacy concerns.