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Diff Viewer

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About Diff Viewer

Diff Viewer compares two blocks of text or code side by side and highlights every addition, deletion, and modification between them. It uses the same diffing algorithm found in professional version control tools, presenting changes in an intuitive visual format. Developers, writers, and QA engineers use it to quickly spot differences between file versions, configurations, or any two text documents.

Key Features

  • Side-by-side and unified diff views for flexible comparison
  • Color-coded highlighting: green for additions, red for deletions, yellow for modifications
  • Line-by-line and character-level diff detection for precise change identification
  • Line numbers on both sides for easy reference when discussing changes
  • Ability to ignore whitespace differences for cleaner comparisons
  • Handles large files with thousands of lines without performance issues

How to Use Diff Viewer

  1. 1

    Paste the original text

    Copy the original version of your text or code into the left (or 'before') input panel.

  2. 2

    Paste the modified text

    Copy the updated version into the right (or 'after') input panel for comparison.

  3. 3

    Click Compare

    Press the Compare button to generate a detailed diff showing all differences between the two versions.

  4. 4

    Review highlighted changes

    Scan the color-coded output where additions appear in green, deletions in red, and modifications in yellow for quick identification.

  5. 5

    Toggle view modes

    Switch between side-by-side view (for spatial comparison) and unified view (for a compact, single-column diff) depending on your preference.

Common Use Cases

Code Review Without Git

Compare two code versions when you do not have access to a Git repository, such as when reviewing code sent via email or shared in a document.

Configuration Change Auditing

Diff production and staging configuration files to verify that only intended changes were made before a deployment.

Database Schema Comparison

Compare SQL schema dumps from different environments to identify table or column differences that need to be migrated.

Content Editing Review

Compare draft and final versions of articles, documentation, or legal documents to see exactly what was added, removed, or reworded.

Why Use Our Diff Viewer

Compare any two text documents instantly without installing Git or a desktop diff tool. Both side-by-side and unified views with character-level highlighting give you more precision than most free online comparators. The whitespace-ignore option is especially useful for comparing code reformatted across different editors or operating systems.

Compare Sensitive Files Without Uploading

Configuration diffs often reveal environment secrets, database credentials, and infrastructure details. The Diff Viewer compares text entirely in your browser, so neither version of your content is ever transmitted to a server. Safely diff production configs, private contracts, and internal documents.

Frequently Asked Questions

Can I compare files in different programming languages?
Yes. The diff tool works on plain text, so it can compare any two text documents regardless of language. However, syntax highlighting is based on the content type you select.
What does 'ignore whitespace' do?
When enabled, the tool treats differences in spaces, tabs, and blank lines as insignificant. This is useful when comparing code that may have different indentation styles but is otherwise identical.
Can I use this to compare binary files?
No. This tool is designed for text-based content only. Binary files like images, PDFs, or compiled executables cannot be meaningfully compared with a text diff tool.

Last updated: April 6, 2026