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Compare Text - Highlight Difference

Compare two texts and instantly highlight every added, removed, or changed word. Free browser-based text diff tool — no uploads, no signup.

Quick Answer

The Compare Text Tool highlights differences between two text inputs side by side — marking additions in green and deletions in red at the word or character level. Use it to proofread edits, compare document versions, review code changes, and spot subtle wording differences.

Compare Text Difference

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What Is the Compare Text Tool?

The Compare Text - Highlight Difference tool finds exactly what changed between two pieces of text. Paste your original and modified versions side by side, click Compare, and instantly see every added word highlighted in green and every removed word struck through in red. It works for any plain text — documents, code, emails, or spreadsheet data — directly in your browser with no uploads required.

How to Compare Two Texts Online

  1. Original Text: Paste your baseline version into the left input box.
  2. Modified Text: Paste your edited version into the right input box.
  3. Compare: Click the "Compare Texts" button.
  4. Review Changes: Scroll to the Comparison Results panel — green highlights show additions, red strikethroughs show deletions. Use the "Copy Result" button to copy the resolved output.

Where Can You Use a Diff Tool?

Code Reviews

Spot tiny syntax changes, missing semicolons, or newly added functions between two nearly identical scripts — without opening a full code editor.

Document Revisions

See exactly what an editor changed in your essay, article, or business proposal without needing track-changes in Word or Google Docs.

Legal & Contract Drafts

Compare two versions of a contract clause or legal brief to confirm which specific words were added, removed, or modified between drafts.

Translation QA

Compare source and translated text to verify structure consistency, or check two translation versions against each other to find discrepancies.

Understanding the Color Coding

  • Green highlight: A word or token was added in the modified version — it did not exist in the original.
  • Red strikethrough: A word or token was deleted from the original and does not appear in the modified version.
  • No highlight: The word is identical in both versions and remained unchanged.
  • Red + Green pair: A word was replaced — the old version is shown in red, and the new version is shown in green immediately after it.

Best Practices and Limitations

The comparison runs 100% locally in your browser using a Longest Common Subsequence (LCS) algorithm — no text is ever uploaded to a server, making it completely safe for sensitive documents, private code, or NDA-protected material.

The tool compares at the word and whitespace token level, not line-by-line. This means minor word changes within a paragraph are detected precisely. For extremely large documents (thousands of words), the comparison may take a moment — this is normal. The tool focuses on plain-text content only; HTML formatting, font styles, and colors are not compared.

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Frequently Asked Questions

Is my data secure when I compare texts?+

Yes, completely secure. The comparison runs 100% locally in your browser using a Longest Common Subsequence (LCS) algorithm. No text is ever uploaded to a server — safe for confidential documents, private code, and NDA-protected content.

Can this tool compare code?+

Yes. Paste two versions of a code snippet to immediately see which lines, variables, or functions were added or removed. It works for any plain text including JavaScript, Python, SQL, HTML, and JSON.

What do the colors mean in the comparison results?+

Green highlight = a word was added in the modified version. Red strikethrough = a word was deleted from the original. No highlight = the word is identical in both versions. A red+green pair means a word was replaced.

Does it compare formatting differences like bold or font size?+

No. This tool compares plain text content only. Formatting, font styles, colors, and HTML tags are ignored — it focuses entirely on what words were added, removed, or changed.

Is there a word limit for comparison?+

There is no hard limit. The LCS algorithm works well for typical document lengths. For extremely large texts (tens of thousands of words), the comparison may take a second or two since everything runs locally in your browser.