Text Diff
Compare two text blocks line by line. Additions in green, deletions in red. LCS algorithm — same as Git.
About This Tool
The DevKit4You Text Diff tool helps you compare two blocks of text quickly and accurately. It highlights changes line by line, making it easy to identify additions, deletions, and modifications between two versions of content.
Whether you're reviewing code changes, editing documents, comparing configuration files, or checking text revisions, this tool provides a clean and readable comparison experience directly in your browser — no uploads, no accounts, no server processing required.
How to Use
Paste the first version of your text into the Original (A) panel. This is the baseline — what the text looked like before changes.
Paste the updated version into the Modified (B) panel. This is the revised version you want to compare against the original.
Toggle Ignore whitespace if you want lines that differ only in leading or trailing spaces to be treated as identical — useful for comparing code that was reformatted without logical changes.
Press COMPARE to run the diff. Added lines appear in green with a + prefix, removed lines in red with a - prefix, and unchanged lines in neutral. The stats badge shows the total count of additions and deletions.
Key Capabilities
Uses the Longest Common Subsequence algorithm — the same approach used by Git, SVN, and Unix diff utilities. Produces minimal, accurate diffs that correctly identify what actually changed rather than just where lines differ.
Added lines are highlighted in green with a + prefix, removed lines in red with a - prefix, and unchanged lines in neutral grey. The result is immediately scannable without needing to read every line.
Compare plain text, source code, JSON, XML, HTML, YAML, Markdown, log files, and configuration files. Any content that can be pasted as text works — no file size limit, no format restrictions.
The "Ignore whitespace" option strips leading and trailing spaces before comparing each line. This prevents formatting-only changes (like reindentation) from cluttering the diff output with false positives.
Example Comparison
Here's what a typical diff looks like. Original (A) on the left, Modified (B) on the right:
The quick brown fox
jumps over the lazy dog
This line is unchanged
This line will be removed
Another unchanged line
The quick brown fox
jumps over the lazy cat
This line is unchanged
This line was added instead
Another unchanged line
And a brand new line
The diff output would show: "lazy dog" → "lazy cat" as a change, the removed line in red, the added lines in green, and unchanged lines in neutral.
Privacy & Transparency
Your text never leaves your device. All comparison logic runs locally in your browser using client-side JavaScript. Nothing is transmitted to any server at any point.
We do not save compared text, file history, or comparison results. Nothing you enter is retained after you close or refresh the page.
The tool operates entirely independently. No data is sent to third-party diff services, cloud processing, or external libraries beyond what is loaded with the page.
The tool simply compares the text you provide and displays detected differences without modifying, logging, or analyzing your content in any other way.
🔒 Safe & Secure
All diffing runs entirely in your browser. Your text is never uploaded, stored, or transmitted. This makes it safe to compare sensitive content such as API responses, private documents, or proprietary source code.
✅ Completely Free
Our tool is free to use with no limits on text size, comparison count, or features. No account, no signup, no API key required — open the page and compare immediately.