📄 Original
📄 Modified

About Code Comparison

A diff tool compares two texts line by line and highlights the differences. It identifies lines that were added, removed, or modified — essential for code reviews, tracking changes, and understanding what changed between two versions of a file.

✓Side-by-side & inline views
✓Ignore whitespace & case options
✓File upload support
✓100% client-side processing

Complete Guide to Code Diff & Text Comparison

Free Online Code Diff Tool

Our code diff tool compares two pieces of text or code and highlights every difference. Additions are shown in green, removals in red, and modifications in yellow. Choose between side-by-side view for easy visual comparison or inline view for a compact unified diff. Upload files directly or paste your code — everything is processed in your browser.

What Is a Diff?

A "diff" (short for difference) is the output of comparing two files or texts. The concept originated with the Unix diff command created in the 1970s. Today, diff algorithms are at the heart of version control systems like Git, code review platforms, and merge tools.

The standard diff format uses + for added lines, - for removed lines, and unchanged context lines. This is the format used by git diff, GitHub pull requests, and most code review tools.

How to Use the Diff Tool

  1. Enter Original: Paste the original code or text in the left panel, or upload a file.
  2. Enter Modified: Paste the modified version in the right panel, or upload a file.
  3. View Differences: The diff is computed automatically. Lines are highlighted by type: green (added), red (removed), yellow (modified).
  4. Switch Views: Toggle between side-by-side and inline (unified) views.
  5. Options: Enable "Ignore whitespace" to skip spacing changes, or "Ignore case" to treat upper and lowercase as equal.
  6. Copy: Copy the unified diff output to your clipboard for pasting into commit messages, reviews, or documentation.

Diff View Modes

⬜ Side by Side

  • Original text on the left, modified on the right
  • Easy to visually compare corresponding lines
  • Best for reviewing small to medium changes
  • Line numbers displayed for both sides
  • Color-coded backgrounds for each change type

📄 Inline (Unified)

  • All changes in a single column
  • Removed lines shown in red, added in green
  • More compact, less horizontal scrolling
  • Similar to git diff output
  • Best for reviewing line-by-line diffs

Common Use Cases

Code Reviews: Compare the original and modified versions of source code to review changes before merging. Quickly spot what was added, removed, or changed.

Configuration Changes: Compare config files (JSON, YAML, .env) to identify differences between environments (development vs. production) or before/after changes.

Debugging:Compare working code with broken code to find what change introduced a bug. Useful when you don't have version control history.

Document Comparison: Compare two versions of a document, contract, or specification to see what was added or removed.

Database Schema Comparison: Diff SQL schema files to understand what migrations need to be created between database versions.

API Response Comparison: Compare API responses from different endpoints or versions to verify data consistency.

Why Use Our Diff Tool?

Instant Comparison: Differences are computed in real time as you edit. No need to submit a form or wait for processing.

Two View Modes: Choose side-by-side for visual comparison or inline for a compact unified diff.

Smart Options: Ignore whitespace differences or case sensitivity to focus on meaningful changes.

File Upload: Upload files directly from your computer instead of copy-pasting.

Copy Diff Output: Copy the unified diff format to clipboard for pasting into tickets, docs, or chat.

100% Privacy: All comparison happens in your browser. Your code is never uploaded or stored on any server.

Perfect For

  • Software developers & engineers
  • Code reviewers
  • QA testers comparing outputs
  • DevOps engineers diffing configs
  • Database administrators
  • Technical writers
  • System administrators
  • Content editors
  • Legal teams comparing contracts
  • Students comparing assignments
  • Anyone comparing text versions
  • Open-source contributors

🔒 100% Privacy Guaranteed

All text comparison is performed entirely in your web browser using JavaScript. Your code and documents are never uploaded to our servers, stored in databases, logged, or transmitted to any third party. Everything happens locally on your device.

Related Developer Tools

JSON Formatter

Format, validate, and beautify JSON data with syntax highlighting.

.*/re/g

Regex Tester

Test and debug regular expressions with real-time match highlighting.

64

Base64 Encoder/Decoder

Encode and decode Base64 strings online with real-time conversion.

Markdown Editor

Write and preview Markdown with live rendering and HTML export.

#

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hash values.