Text Diff Checker
Compare two blocks of text and see differences highlighted line by line. Added, removed, and unchanged lines shown in color. Free online diff tool.
About this tool
The Text Diff Checker compares two blocks of text line by line and highlights the differences. Added lines are shown in green, removed lines in red, and unchanged lines in the default color. This is useful for comparing code revisions, document drafts, or any text that has been edited.
The comparison algorithm uses Longest Common Subsequence (LCS) to produce accurate, minimal diffs. All processing happens in your browser. No text is sent to any server.
Frequently Asked Questions
How does the diff comparison work?
The tool compares your two texts line by line. Lines only in the original are marked red (removed). Lines only in the modified text are marked green (added). Matching lines are shown in gray.
Can I compare large files?
Yes. The comparison runs entirely in your browser with no size limits. Large texts with thousands of lines are handled efficiently.
Is my text data private?
Yes. Both texts are compared locally in your browser. No data is sent to any server. This tool is safe for comparing sensitive documents or code.