Text Diff Viewer

Compare two text blocks or code snippets to find differences. Privacy-first online diff tool with side-by-side comparison. 100% client-side, no data sent to servers.

Original Text

Modified Text

About Text Diff Viewer

Text Diff Viewer is a free online tool that compares two text blocks or code snippets to find differences instantly. It highlights added lines in green, removed lines in red, and unchanged lines remain neutral. Whether you need to compare code versions, check document revisions, or find changes between two files, this tool handles it all. All processing happens entirely in your browser — your text never leaves your device, ensuring complete privacy and security.

Features

Side-by-Side Comparison — View original and modified text with clear visual differences
Color-Coded Results — Added lines in green, removed lines in red, unchanged lines neutral
Line-by-Line Diff — Precise comparison showing exactly which lines changed
Code-Friendly — Works with any programming language, JSON, XML, HTML, CSS, and more
One-Click Compare — Instant results with a single button click
Copy & Download — Copy results to clipboard or download as a text file
100% Client-Side — No server uploads, your data stays private and secure
Cross-Platform — Works on any device with a modern web browser
Zero Setup — No installation, no registration, no ads
Free Forever — Unlimited comparisons with no usage limits

How to Use

Paste or type your original text into the left textarea
Paste or type the modified text into the right textarea
Click the "Compare" button to process the diff instantly
View the color-coded results showing all additions and deletions
Use "Clear" to reset both inputs and start a new comparison

Common Use Cases

Compare code versions to track changes between commits or file versions
Check document revisions to see what was added or removed
Review configuration file changes before deploying to production
Compare API responses to debug differences between environments
Validate data migrations by comparing before and after datasets
Proofread translations by comparing original and translated text

Frequently Asked Questions

What is a diff tool and how does it work?

A diff (difference) tool compares two text blocks and highlights the differences between them. Our tool uses line-by-line comparison to show added lines in green, removed lines in red, and unchanged lines in a neutral color. This makes it easy to spot exactly what changed between two versions of text or code.

Is my data safe when using this diff viewer?

Absolutely. All comparison processing happens entirely in your browser using JavaScript. Your text is never sent to any server, stored in a database, or shared with third parties. This ensures complete privacy and security, making it safe to compare sensitive code or confidential documents.

Can I compare programming code with this tool?

Yes, this tool works perfectly with all programming languages including JavaScript, Python, Java, C++, HTML, CSS, JSON, XML, SQL, and more. It treats all input as plain text, so it works with any code format. For syntax-aware diffs, you may want to use a dedicated IDE diff tool.

Can I upload files directly to compare?

Currently, you need to copy and paste the content of both files into the text areas. Direct file upload support is planned for a future update. For now, simply open your files, select all content (Ctrl+A), copy (Ctrl+C), and paste into the appropriate textarea.

What is the maximum text size I can compare?

The tool can handle text up to several megabytes in size. However, very large files (1MB+) may take longer to process depending on your device's performance. All processing remains client-side, so the limit depends on your browser and device memory.

Can I download or save the diff results?

Yes. After comparing, you can copy the results to your clipboard using the copy button, or download the output as a text file. This makes it easy to share differences with teammates or save them for documentation.

Does this tool show character-level or word-level differences?

Currently, this tool shows line-level differences — it highlights entire lines that were added or removed. Character-level and word-level diff granularity is planned for a future update to show more precise changes within lines.

Is this tool free to use?

Yes, Text Diff Viewer is completely free to use with no registration required, no ads, and no usage limits. You can compare as many text blocks as you need, whenever you need.