Text Diff Checker
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Need to see what changed between two versions of a document? Or debugging why one code snippet works and another doesn't? Our Diff Checker is your ultimate comparison tool. Paste your original text on the left and the new version on the right, and we'll instantly highlight every addition, deletion, and modification with clear, color-coded markers.
We specialize in precise, line-by-line and character-by-character analysis. Our tool uses advanced algorithms to find even the smallest changes—like a missing comma or a different capital letter—that are impossible to spot with the naked eye. It's the essential utility for developers reviewing code, editors checking revisions, and students comparing draft versions of their essays.
Privacy is natively built-in. This tool runs entirely in your local browser. Your code, drafts, and sensitive documents never leave your device and are never sent to our servers. Safely compare internal reports or proprietary code with 100% confidence. Fast, free, and completely secure—spot the differences in one click.
How to compare two texts for differences online
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Paste Original Text: Put your 'before' or reference text into the left-side input area.
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Paste Changed Text: Put your 'after' or new version into the right-side input area.
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Auto-Analysis: The tool instantly calculates the differences as soon as both sides have text.
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Review Highlights: Green markers show additions, while red markers show deleted content.
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Switch Views: Choose between 'Side-by-Side' or 'Inline' view to see the changes in the layout that works best for you.
Why Use This Tool?
- ✓Instand highlighting of additions and deletions
- ✓Both Side-by-Side and Inline comparison views
- ✓Character-level precision for finding tiny typos
- ✓Option to ignore whitespace-only changes
- ✓100% private—all processing happens on your device
- ✓Compatible with text, code, and document drafts
- ✓High performance for large file comparisons
- ✓Always free with no registration required
Getting the most from your comparison
Line vs Character diffs
Line-level diffs help you see which whole lines moved or changed. Character-level diffs zoom in to show you exactly which letter inside a line was modified—perfect for finding typos.
Side-by-Side View
This is great for comparing two documents where lots of lines have moved. It gives you a clear visual anchor to see how the flow has changed.
Inline View
The inline view shows changes stacked on top of each other. It's often easier for developers to read when checking small code modifications.
Ignoring Whitespace
Sometimes a file changes just because of spaces or tabs. We offer options to ignore these 'invisible' changes so you can focus on the actual content.
Comparing Code
When debugging, even a single space in the wrong place can break a program. Our precise character highlighting makes these invisible bugs easy to find.
Local security for code reviews
Since everything is processed locally via JavaScript, your proprietary source code and sensitive internal documents are never exposed to our servers.
Frequently Asked Questions
Is the diff checker free?
Yes, 100% free with no limits on how much text you can compare.
What do the colors mean?
Typically, red highlights indicate text that was deleted from the original version, and green highlights show new text that was added.
Can I compare code files?
Absolutely. It's one of the most common uses. It works with any programming language since it treats everything as plain text.
Is there a limit on text length?
No, but extremely large files (thousands of lines) may take a brief moment for your browser to calculate the differences.
Will you store the text I compare?
Never. All comparison logic happens in your browser's RAM. We don't see, log, or store anything you paste.
Does it show character-level changes?
Yes. Beyond just identifying that a line changed, it zooms in to show you the specific characters that are different.
Does it work with different file encodings?
Yes. As long as you can copy the text, our tool can compare it regardless of the original file format.
Can I ignore spaces and tabs?
Many users find it helpful to toggle 'ignore whitespace' to hide changes that don't affect the actual meaning of the text.
Does it work on my phone?
Yes, although side-by-side comparison is usually much easier to read on a larger desktop screen.
Why is my text looking shifted?
If a large chunk of text was added at the top, the rest of the document will shift. Our tool uses smart alignment to keep matching lines as close together as possible.
Can I save the diff report?
You can take a screenshot or print the page to share the highlighted differences with your team.
Do I need to download an app?
No. Everything works right in your web browser with no extensions or software installations required.
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