How to Compare Two Text Files Online
A step-by-step tutorial for comparing text files online using DiffText Pro. Learn how to quickly identify differences between documents, code files, and text content in your browser.
Table of Contents
Getting Started
DiffText Pro is a free online tool that lets you compare two text files directly in your browser. No installation required, no sign-up needed, and your data never leaves your device.
What you'll need:
- Two text files, documents, or text snippets you want to compare
- A modern web browser (Chrome, Firefox, Safari, or Edge)
- A few minutes of your time
Performing a Basic Comparison
The easiest way to compare text is to paste it directly into the comparison tool:
- Visit DiffText Pro - Navigate to the homepage
- Paste Original Text - In the left panel labeled "Original Text", paste or type your first version
- Paste Modified Text - In the right panel labeled "Modified Text", paste or type your second version
- View Results - The comparison automatically updates as you type, showing differences highlighted in color
💡 Tip: The comparison happens instantly in your browser. Your text is never uploaded to any server, ensuring complete privacy.
Uploading Files
If your text is stored in files, you can upload them directly:
- Drag and Drop - Drag your first file into the "Original Text" drop zone
- Or Click to Browse - Click "Choose File" to select a file from your computer
- Repeat for Second File - Upload your second file to the "Modified Text" panel
- Automatic Detection - The tool automatically detects the file type and applies syntax highlighting if needed
Supported file formats:
- Plain text (.txt)
- Markdown (.md)
- JSON (.json)
- CSV (.csv)
- Code files (.js, .py, .java, .html, .css, .xml, and 50+ more)
⚠️ Note: Maximum file size is 10 MB per file. For larger files, consider using a desktop diff tool.
Using Comparison Options
Customize your comparison to focus on what matters most:
- Diff Mode - Choose between word, character, line, or sentence-level comparisons
- Ignore Whitespace - Skip spaces, tabs, and line breaks in comparisons
- Ignore Case - Treat uppercase and lowercase letters as identical
- Ignore Line Endings - Handle Windows/Unix/Mac line ending differences
- Enable Syntax Highlighting - Color-code your code with language-specific highlighting
To access these options, click the "Comparison Options" button at the top of the page.
Understanding the Results
The comparison results use color coding to make differences easy to spot:
- Green - Text that was added in the modified version
- Red - Text that was deleted from the original version
- Yellow - Text that was modified or changed
- No color - Text that remained unchanged
Example: Comparing two versions of a document
At the top of the results, you'll see statistics showing:
- Number of additions (lines added)
- Number of deletions (lines removed)
- Number of modifications (lines changed)
- Number of unchanged lines
Exporting Your Comparison
Save or share your comparison results in multiple formats:
- Copy to Clipboard - Click "Copy" to copy the comparison text
- Export to HTML - Save as a standalone HTML file with styling
- Export to PDF - Generate a PDF document of your comparison
- Export to JSON - Download structured JSON data for programmatic use
- Export to Unified Diff - Create a Git-compatible .diff file
- Share via URL - Generate a shareable link (with optional password protection)
To export, click the "Export" button above the comparison results and choose your preferred format.
Pro Tips
Use the Right Diff Mode
Word mode is best for prose and documents. Character mode gives the most detailed view. Line mode works well for code. Sentence mode is ideal for comparing paragraphs.
Enable Syntax Highlighting for Code
When comparing code files, enable syntax highlighting and select the appropriate language. The tool supports automatic language detection for most common programming languages.
Ignore Formatting Changes
If you only care about content changes (not formatting), enable "Ignore Whitespace" and "Ignore Line Endings" to filter out spacing and line break differences.
Switch Between View Modes
Try both side-by-side and inline views to see which works better for your comparison. Side-by-side is great for reviewing, while inline is better for understanding the flow of changes.
Your Data Stays Private
All comparisons happen in your browser using JavaScript. Your text is never uploaded to any server, making it safe to compare sensitive documents, source code, or confidential information. For more details about protecting shared assets, check out PixelProbe to audit metadata before you distribute files.
Ready to Compare Your Text Files?
Start comparing now - it's free, fast, and private!
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