The Diff Checker Tool is a lightweight, web-based utility designed to compare two blocks of text and highlight their differences. It provides an intuitive interface for users to paste texts, compare them, and view the changes in a clear, colour-coded format. The tool compares multiline texts, programming code, HTML, or other textual content. All processing is done client-side, right on the browser.
Compare two texts or code snippets and highlight the differences between them.
Original Text
Modified Text
Differences
Diff Checker Tool Features:
- Both Text and Code Difference Detection
- Automatically detects if a code snippet is provided and shows the code comparison result syntax highlighted.
- Smart whitespace handling with configurable sensitivity.
- Multiline Support
- Handles multi-line inputs seamlessly, which makes it suitable for code, HTML, or large documents.
- Word-level difference support
- The tool will analyze and show word-level differences for every line change.
- Color-Coded Differences
- The result section will highlight added lines in green.
- The result section will highlight removed lines in red.
- Unchanged lines are displayed as-is.
- Whitespace Handling
- Option to ignore or consider whitespace differences
- The default setting ignores whitespace for code comparison convenience
- Toggle available for exact whitespace matching when needed
- Difference Navigation
- Use the “Prev” and “Next” buttons above the results to jump between highlighted differences. A counter shows the current difference number and the total count.
- Cross-Browser Compatibility
- Works in all modern browsers without requiring additional plugins or configurations.
- Sophisticated Diff Algorithm
- Uses the Myers difference algorithm-based javascript library for change detection.
Usage Example
Step-by-Step Guide
- Input Texts
- Paste the first text block into the left text-area labelled “Paste your first text here…”
- Paste the second text block into the correct text-area labelled “Paste your second text here…”
- “Ignore whitespace” Configuration:
- Checked (default): Ignores differences in spaces, tabs, and line endings
- Unchecked: Shows all whitespace differences
- Compare Texts
- Click the “Compare” button to analyze the differences between the two texts.
- View Results
- The differences will be displayed below the button in a styled output area.
- Added lines will appear in green, removed in red, and unchanged lines will remain unstyled.
Example:
Text 1:
function greet(name) {
console.log("Hello, " + name);
}Code language: JavaScript (javascript)Text 2:
function greet(name) {
console.log("Hi, " + name);
}Code language: JavaScript (javascript)Example diff checker result output:
Limitations:
- Performance with Large Inputs
- While the tool efficiently handles moderate-sized texts, extremely large inputs may impact performance due to the lack of optimization for large datasets.
Privacy & Security
- 🔒 100% Client-Side Processing: All text comparisons are performed 100% locally in your browser
- 🚫 No Data Storage: Your text content is never saved or transmitted to any server
- 💻 Offline Capability: Works without an internet connection once loaded
- 🔐 Data Privacy: No cookies, tracking, or data collection of any kind
Diff Checker FAQs
Yes! Once the page loads, all comparisons happen locally in your browser, so you can use it without an internet connection (e.g., by saving the page or bookmarking it for later).
It handles multiline text and code well (including syntax highlighting), but performance may slow with extremely large inputs (tens of thousands of lines) since everything processes in-browser. For huge files, consider splitting them or using a desktop diff tool.
This is intentional for cleaner code comparisons—minor formatting changes don’t clutter the results. You can toggle the “Ignore Whitespace” option off if you need exact matching, including every space and newline.
Feedback
Please message us for any bug reports/feature requests and/or feedback.