Text Diff Checker

Paste two versions of your text and instantly see what changed. Added lines are highlighted green, removed lines red, and unchanged lines are shown in gray — all in your browser with no data sent to a server.

How to Use the Text Diff Checker

  1. Paste your original text into the left textarea labeled "Original Text".
  2. Paste the modified version into the right textarea labeled "Modified Text".
  3. Click "Compare" to see the differences highlighted line by line. Green lines were added, red lines were removed.

Features

Text diff checker: practical uses

Use text diff checker when you need a fast, clear, private result without creating an account. This page also supports related needs like compare text online, text comparison, diff checker so you can choose the right workflow.

When it helps

For the next step, try Word Counter, Character Counter, Text Case Converter, Roman Numeral Converter.

Frequently Asked Questions

How does the diff algorithm work? +
The tool uses the Longest Common Subsequence (LCS) algorithm, the same foundation used by tools like git diff. It finds the largest set of lines that appear in both texts in the same order, then marks everything else as added or removed.
Is my text sent to a server? +
No. All comparison happens entirely inside your browser using JavaScript. Your text never leaves your device, making it safe to use with sensitive or confidential content.
Can I compare code files? +
Yes. The tool works with any plain text, including source code in any language, JSON, XML, YAML, configuration files, and more. Simply paste the file contents into both text areas.
What does the "Unchanged" count mean? +
Unchanged lines are lines that exist in both the original and modified text at corresponding positions. A high unchanged count means the two texts are very similar.
Is there a size limit for the text I can compare? +
There is no enforced limit, but very large texts (thousands of lines) may take a moment to process due to the LCS algorithm's complexity. For best performance, compare texts under a few thousand lines.

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