How to Compare Texts and Highlight Differences Online
Proofreading revisions between drafts, verifying copy changes before publishing, and reviewing code diffs shouldn't require installing bulky desktop software. Our private, in-browser Online Text Compare tool highlights additions, deletions, and common lines side-by-side with zero data leaving your machine.
Step-by-Step Instructions
- 1
Enter Text 1 & Text 2
Paste your original text in the left panel and the revised or updated text in the right panel.
- 2
Click Compare
Click the Compare button in the header toolbar to immediately compute the exact differences.
- 3
Review Highlighted Changes
Added text is clearly highlighted in green, while deleted or replaced words are highlighted in red.
- 4
Copy or Download Results
Use the toolbar buttons to copy the formatted comparison or download the diff summary directly.
Key Features & Benefits
Precise Character & Word Diff
Pinpoints single character edits, word deletions, and full paragraph restructurings accurately.
100% Client-Side Privacy
Compare sensitive legal contracts, non-disclosure agreements, and private code with zero server uploads.
One-Click Text Swapping
Reverse the comparison direction in one click with the dedicated Swap Texts button.
Print & Export Ready
Export diff outputs or print clean side-by-side comparison sheets directly from your browser.
Dark Mode Support
Easy-on-the-eyes dark mode theme optimized for long code review sessions and low-light environments.
High-Speed Processing
Engineered with jsdiff for sub-second comparison performance even on long-form manuscripts.
Frequently Asked Questions
Can I use this diff tool to compare programming source code?
Yes. Online Text Compare works with programming languages (JavaScript, Python, C++, Go), HTML/CSS, SQL queries, and configuration files like YAML and INI.
Is my confidential text uploaded or logged on your servers?
No. The diff computation executes 100% inside your browser using client-side JavaScript. Your text is never sent over the internet.
How do the colors indicate changes in the text diff?
Green highlights indicate text that was added in Text 2. Red highlights indicate text from Text 1 that was removed or modified.
Is there a limit to how much text I can compare?
There are no artificial word or character limits. The tool comfortably handles tens of thousands of words in a single comparison.