Text Diff Checker

Compare text differences side by side with highlighting and line numbers

Left side of comparison
Right side of comparison
How to Use the Text Diff Checker
Compare two texts and see their differences highlighted with colors

1. Add Your Texts

  • • Type or paste text in the left and right boxes
  • • Or upload text files using the upload buttons
  • • Comparison starts automatically when both texts are present

2. Understand the Colors

  • Green: Lines that were added
  • Red: Lines that were deleted
  • Yellow: Lines that were modified
  • • Gray: Lines that stayed the same

3. Customize the View

  • Context Lines: How many unchanged lines to show around changes
  • View Mode: Side-by-side or unified display
  • Diff Mode: Compare by line, word, or character
  • Options: Ignore case, whitespace, show line numbers

4. Export Results

  • • Download as patch file for version control
  • • Export as HTML for sharing or documentation
  • • Copy text directly from the comparison view

💡 Tip: Try changing the "Context Lines" setting to 0 to see only the changed lines, or increase it to see more surrounding context. The "Show Unchanged Lines" toggle controls whether unchanged lines appear in the comparison at all.

Privacy Note: All text comparison happens entirely in your browser. No data is sent to any servers.

How to Compare Text Differences Online Free

Our text diff checker makes it easy to identify differences between two pieces of text. Whether you're comparing code, documents, or any text content, our tool provides comprehensive side-by-side and unified diff views with advanced options for precise comparison. All processing happens in your browser for complete privacy.

Advanced Text Comparison Features

Multiple View Modes

  • • Side-by-side comparison for easy visual comparison
  • • Unified diff view for traditional patch-style output
  • • Line numbers for precise reference
  • • Syntax highlighting for code differences

Flexible Comparison Options

  • • Line-by-line, word-by-word, or character-level diff
  • • Ignore whitespace and case sensitivity options
  • • Configurable context lines for focused viewing
  • • Search functionality within differences

File Upload and Export Support

Upload text files directly for comparison or paste content manually. Our diff checker supports all common text file formats including source code files (.js, .ts, .py, .java, .cpp), configuration files (.json, .xml, .yaml), and documents (.txt, .md). Export your diff results in multiple formats including unified patch files, HTML reports, and plain text.

Perfect for Developers and Content Creators

Code Review

Compare different versions of source code, review changes, and identify modifications in programming files with syntax-aware highlighting.

Document Editing

Track changes in documents, compare draft versions, and collaborate on content creation with clear visual difference indicators.

Configuration Management

Compare configuration files, identify setting changes, and maintain consistency across different environments and deployments.

Secure and Private Text Comparison

Your privacy is our priority. All text comparison and diff generation happens entirely in your browser using advanced JavaScript algorithms. No text content is ever transmitted to our servers, ensuring your sensitive documents and code remain completely private and secure. The tool works offline once loaded, making it perfect for confidential file comparisons.

Frequently Asked Questions

What file formats can I compare?

You can compare any text-based files including source code (.js, .ts, .py, .java, .cpp), markup files (.html, .xml, .md), configuration files (.json, .yaml, .ini), and plain text documents. Binary files are not supported.

Is there a file size limit?

For optimal performance, we recommend files under 1MB. Larger files may work but could cause slower processing. The tool handles most typical document and source code file sizes without issues.

Can I export the diff results?

Yes! You can export diff results in multiple formats: unified patch format (.patch), HTML reports with styling, plain text summaries, and JSON data. All exports include statistics and can include timestamps.

What's the difference between view modes?

Side-by-side mode shows both texts in parallel columns for easy visual comparison. Unified mode displays differences in a single column using traditional patch format with +/- indicators, similar to Git diffs.

How accurate is the diff algorithm?

We use the Myers' diff algorithm, the same algorithm used by Git and other professional version control systems. This ensures highly accurate and optimal difference detection even for complex text changes.

Can I ignore whitespace differences?

Yes, you can configure the diff to ignore whitespace changes and case sensitivity. This is especially useful when comparing code where formatting might differ but the actual content is the same.