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Compare text

Diff Viewer

Visually compare differences between two text blocks and instantly identify additions, removals, and changes.
Line breaks and whitespace differences are also highlighted, helping you catch even subtle modifications.

This tool is useful for reviewing documents, proofreading content, and checking revisions in source code or specifications.
All comparisons are performed directly in your browser, and no text is sent to any server.

Guide: How to use & features

  • Paste the original text on the left and the modified text on the right, then click “Show diff.”
  • Additions appear in green and removals in red, making changes easy to spot.
  • After viewing, use the copy buttons under each pane to share either version.
  • Very large inputs may take a few seconds to render—please keep the tab open until it finishes.

Samples: Sample input & output

Compare two short files

Input

Left
console.log("hello");
Right
console.log("hello world");

Output

- console.log("hello");
+ console.log("hello world");

FAQ: Frequently asked questions

  • How are whitespace differences handled?

    Diffs are shown per line and include spaces, tabs, and line breaks. Cleaning up stray whitespace before pasting makes the output easier to read.

  • Is it okay for large snippets?

    Processing happens in the browser; a few thousand lines is typically fine. For bigger files, split them into sections before comparing.

  • Can I save the diff?

    Use copy to grab the rendered diff text. You can also take a screenshot or rely on your browser’s save/share features if needed.

Use cases: Common use cases

  • Comparing config or environment changes

    Quickly diff updated .env or YAML/JSON files to review tweaks and catch unintended edits.

  • Checking generated output

    Paste build artifacts or codegen results to see exactly what changed between runs.

  • Sharing minimal edits

    Extract only the relevant lines as a diff to discuss changes in PR comments or chat.

Notes: Notes & limitations

  • Work stays in your browser

    Inputs and outputs remain local. Closing the tab or clearing cache will remove any temporary state.

  • Validate critical data

    Results are helper outputs—double-check them before sending to production systems or sharing externally.

  • Large payloads depend on your device

    Very large text or files can feel slow in some browsers. Use a desktop environment for heavy workloads.
Result

Text Diff and Comparison Tool

This text diff tool compares two pieces of text and highlights added, removed, and changed lines. It is useful for code snippets, configuration files, documentation drafts, logs, generated output, and any situation where small changes are easy to miss by eye.

When to use it

  • Review code before committing: Compare an old snippet with a new one and catch accidental edits.
  • Check configuration changes: Compare JSON, YAML, .env, server configs, or deployment settings.
  • Edit documentation: See exactly which sentences or lines changed between two drafts.

Review tip

Whitespace, indentation, and line endings can appear as differences. When reviewing a diff, separate meaningful content changes from formatting-only changes so you can focus on the behavior or wording that actually changed.

Articles for this tool

Introduction
2026-01-21

Text Diff Essentials: Efficient Reviews and Change Verification

Spot changes instantly with Diff tools. Learn about line-by-line and character-level comparisons, merging mechanics, and techniques to boost development efficiency.

Development Story
2026-03-09

Safe Without Data Transmission: The Background of Our Browser-based Diff Tool

How we designed a private, high-speed text comparison tool using browser-side computing to prioritize user privacy.

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