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Text Diff Checker

Compare two texts and see the differences highlighted

What is Text Diff Checker?

Compare two blocks of text side by side and instantly see what changed between them. Added lines are highlighted in green, removed lines in red, and unchanged lines are shown normally with line numbers on both sides. Perfect for comparing code revisions, configuration files, document drafts, or any two versions of text. The diff algorithm runs entirely in your browser — your text is never sent to any server.

How to Use Text Diff Checker

  1. 1Paste your original text into the left textarea labeled 'Original Text'
  2. 2Paste the modified text into the right textarea labeled 'Modified Text'
  3. 3Click 'Compare' to generate the diff output
  4. 4Review the highlighted results: red for removed lines, green for added lines, and plain for unchanged lines

Frequently Asked Questions

A diff checker compares two pieces of text and highlights the differences between them. Lines that were removed from the original are shown in red, lines that were added in the modified version are shown in green, and unchanged lines are displayed normally. This is the same concept used in version control systems like Git.
This tool uses a Longest Common Subsequence (LCS) based algorithm to find the optimal set of changes between the two texts. It compares the texts line by line and identifies which lines were added, removed, or kept unchanged, producing a minimal and accurate diff output.
Yes. The diff checker works with any plain text including source code, configuration files, JSON, XML, CSV, and more. It preserves whitespace and indentation so you can see exactly what changed in your code.
Absolutely. All comparison processing happens locally in your browser using JavaScript. Your text is never transmitted to any server, making this tool safe for comparing sensitive or proprietary content.

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