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Compare Two Texts

Paste your original text on the left and the modified version on the right, then click Compare . Matching words are highlighted green , removed words in red , and added words in blue . A stats bar shows line-level totals at a glance.

Original Text
Modified Text

What is a Text Diff Checker?

A Text Diff Checker is a tool that compares two versions of text and highlights exactly what changed between them. Unlike basic diff tools that only flag entire changed lines, IndexCraft's checker uses a word-level LCS (Longest Common Subsequence) algorithm to show exactly which words match, which were removed, and which were added — even within the same line.

This makes it ideal for spotting a single changed word in a long paragraph, rather than having to manually re-read entire blocks of text.

How to Use the Text Diff Checker

  1. Paste your original text into the left textarea.
  2. Paste your modified text into the right textarea.
  3. Click Compare to run the diff instantly.
  4. Read the color-coded results: green = match, red = removed, blue = added.
  5. Check the stats bar for total matching, partially changed, removed, and added line counts.

Key Features

Common Use Cases

Code Review Spot changed variable names, values, or logic in source code.
Content Editing Compare drafts of articles, emails, or blog posts word by word.
Legal Documents Identify changed clauses or terminology between contract versions.
Academic Writing Verify essay revisions and confirm edits were applied correctly.
Data Validation Confirm exported files are identical or find exact divergence points.
Translation Review Compare updated translations against previous approved versions.

How the Algorithm Works

IndexCraft's Text Diff Checker runs a two-pass LCS (Longest Common Subsequence) algorithm entirely in your browser:

The result is a precise, human-readable diff that shows even single-word changes within long paragraphs — far more useful than line-only diff tools.

Text Diff Checker – Frequently Asked Questions

A text diff checker compares two versions of text and highlights exactly what changed. IndexCraft's tool works at the word level — matching words are highlighted green, removed words in red, and added words in blue — in a side-by-side panel view.

Paste your original text into the left box and your modified text into the right box on this page, then click Compare. Results appear instantly with word-level color highlighting. No login or install required.

Yes. This tool runs entirely in your browser using JavaScript. Your text is never uploaded to any server, making it completely safe for sensitive documents, legal content, or confidential data.

Green = words that match in both texts. Red = words that appear only in the original (removed). Blue = words that appear only in the modified text (added). Yellow line backgrounds indicate lines that are partially changed.

Yes. The tool works on any plain text — including source code, HTML, JSON, YAML, config files, SQL, and more. It highlights changed variable names, values, or keywords at the word level.

A two-pass Longest Common Subsequence (LCS) algorithm. The first pass identifies matching, added, and removed lines. The second pass performs word-level LCS on partially matching line pairs to highlight exactly which words changed within each line.