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Text Diff Tool for Line-by-Line Comparison

Online text comparison tool with highlighted differences

Line-by-line comparison
Highlight differences
Change statistics
Original Text
Modified Text
Usage Guide

What is Diff?

Diff is a tool for comparing differences between two texts, clearly showing what was added, removed, or modified.

Common Use Cases

  • • Code review
  • • Document version comparison
  • • Config file checking
  • • Contract comparison

Paste two versions of text to see additions and deletions instantly. This online text diff highlights changes without uploading your content.

How to Use This Text Diff Effectively

Paste the original text on the left and the revised text on the right. The tool compares lines and highlights additions in green and removals in red. Use the swap button if you pasted them in the wrong order. If you are comparing long paragraphs, insert line breaks at logical points (sentences, list items, or config entries) so differences are easier to scan. The stats panel shows how many lines were added, removed, or unchanged, which helps you gauge the size of a revision. For clean results, keep consistent formatting in both inputs and avoid extra whitespace unless you want to track it. Once you verify the changes, copy the edited text back into your document.

Why Use an Online Text Diff?

An online text diff is perfect for quick checks when a full Git workflow is too heavy. It runs instantly in the browser, so you can compare versions of a contract, meeting notes, or a config snippet without installing tools. Because everything stays local, sensitive content never leaves your machine. The side-by-side view helps spot missing lines, duplicated items, or accidental edits, and it works equally well for plain text, code fragments, and data files. Whether you are proofreading, reviewing a teammate's notes, or validating a generated output, this tool gives you a fast, private, and dependable comparison.

Features Breakdown

  • Side-by-side diff view with clear line numbers for both versions.
  • Color-coded highlights for additions, deletions, and unchanged lines.
  • Instant swap button to flip original and modified inputs.
  • Change statistics so you can gauge the size of revisions at a glance.
  • Works with any text, from code snippets to documents and config files.
  • Local processing for privacy with no uploads or accounts.

Best Practices for Clean Comparisons

To improve accuracy, normalize line endings (LF or CRLF) before comparing. Trim trailing spaces if they are not meaningful, or keep them if whitespace changes matter in your environment. For large files, compare smaller sections so the line-based algorithm can align matches more clearly. If you are working with JSON or YAML, format them first to make structure changes visible. When you want a semantic diff, use this tool for the first pass, then follow up with a dedicated language-aware formatter. These habits keep the comparison readable and reduce false positives.

FAQ

Q: Is my text uploaded to a server?

A: No. All comparisons run locally in your browser. The text never leaves your device, so you can safely compare sensitive content.

Q: Can I compare code, JSON, or config files?

A: Yes. The diff is line-based and works with any plain text. For structured files like JSON or YAML, format them first to make changes easier to read.

Q: What kind of diff algorithm is used?

A: This tool uses a line-based LCS (Longest Common Subsequence) approach. It is fast and reliable for typical text edits, but for extremely large files a specialized diff tool may perform better.