Original Text
Chars: 0 | Lines: 0
Changed Text
Chars: 0 | Lines: 0
Diff result will appear here
Enter two texts and click "Find Differences" to compare
What Is Diff Checker?
Diff Checker is a text comparison tool that highlights the exact differences between two pieces of text or code. It runs entirely in your browser using the battle-tested diff algorithm — no data is ever sent to a server.
Related Tools
Comparison Modes
- Line Diff — Compares text line by line, ideal for code reviews and configuration file comparisons
- Word Diff — Compares text word by word, highlighting individual word-level changes within sentences
View Options
- Side-by-Side — Displays original and changed text in parallel panels with synchronized scrolling
- Unified — Shows all changes in a single panel with +/- markers and dual line numbers, similar to git diff output
- Responsive layout automatically switches to Unified view on smaller screens
Key Features
- Color-coded highlighting: red for deletions, green for additions
- Line numbers for easy reference in both views
- Synchronized scrolling in Side-by-Side mode
- Real-time statistics showing total changes, additions, and deletions
- File upload support for comparing text files directly
- Sample data for quick demonstration
- Character and line count for both input panels
How to Use
Paste or upload your original text in the left panel and the changed text in the right panel. Select Line or Word diff mode, then click "Find Differences". The result will appear below with color-coded highlighting. Use the Side-by-Side or Unified toggle to switch between view layouts.
Common Use Cases
- Reviewing code changes before committing to version control
- Comparing configuration files across environments (dev, staging, production)
- Checking document revisions and editorial changes
- Verifying API response differences between versions
- Debugging by comparing expected vs actual output
- Comparing SQL queries or database schemas
Frequently Asked Questions
- Is my data sent to any server?
- No. All comparison is performed entirely in your browser using JavaScript. Your text never leaves your device.
- What is the difference between Line Diff and Word Diff?
- Line Diff compares text on a line-by-line basis — if any character in a line changes, the entire line is marked. Word Diff compares at the word level, so you can see exactly which words were added, removed, or changed within a line.
- Can I compare binary files?
- No. Diff Checker is designed for plain text and code. Binary files (images, PDFs, executables) are not supported.
- Is there a file size limit?
- Uploaded files are limited to 5 MB. For very large files, performance depends on your browser and device.
- Can I use this tool offline?
- Yes. Once the page has loaded, Diff Checker works without an internet connection because all processing is client-side.