Is Diff Checker free to use?

Yes, Diff Checker is completely free. No sign-up, no payment, no hidden fees.

Is my text data safe?

Absolutely. All text comparison happens in your browser. Your text never leaves your device and is never uploaded to any server.

What file formats are supported?

Diff Checker supports plain text files including .txt, .md, .html, .css, .js, .json, .xml, .csv, and .log files.

How does the text comparison work?

Diff Checker uses the Myers diff algorithm to find the minimum edit distance between two texts. Differences are highlighted in green for additions and red for deletions.

Compare text.
Spot differences instantly.

A free, private text comparison tool. No sign-up, no uploads - everything happens right in your browser. Compare code, documents, or any text side-by-side.

Start Comparing How It Works

--- Original
- The quick brown fox jumps over the lazy dog.
+ The quick brown fox jumps over the lazy cat.
 Diff Checker is a useful tool for developers.
+ A brand new line added here.

Why Diff Checker?

Everything you need, nothing you don't.

100% Private

Your text never leaves your device for comparison. The diff runs client-side in your browser, with advertising cookies covered separately in our Privacy Policy.

Instant Results

Auto-compare as you type. Real-time diff highlighting with zero latency. No page reloads needed.

4 View Modes

Inline, Line-by-Line, Word Diff, and Side-by-Side. Choose the view that fits your workflow best.

File Upload

Drag and drop or upload .txt, .md, .json, .csv, .xml, .log files. Supports all common text formats.

Detailed Stats

See characters added/removed, similarity percentage, and change count at a glance.

Keyboard Shortcuts

Ctrl+Enter to compare. Full keyboard navigation support. Built for power users.

How It Works

Three simple steps to compare any text.

Paste or upload your texts

Enter two versions of text in the side-by-side panels. Or upload files directly.

Choose your view

Switch between Inline, Line-by-Line, Word Diff, or Side-by-Side views to see differences your way.

Review the results

Added text in green, removed text in red. Stats show exact changes.

Ready to compare?

Free. Private. No sign-up required.

Start Comparing Now

Who Uses Diff Checker?

Built for anyone who works with text.

Developers

Quick diff checks on code, config files, and logs. Compare commits and track changes.

Writers & Editors

Track document revisions. Spot edits between drafts. Verify proofreading changes.

Students

Compare essay drafts. Check citations. Review revisions before submission.

Text Comparison Tips

Choose the right diff view for the kind of change you are reviewing.

Use side-by-side for reviews

Side-by-side comparison is best when you want to scan the original and modified text at the same time. It works well for document revisions, support replies, product copy, and configuration changes.

Use line-by-line for code and logs

Line-by-line diff is useful when line order matters. It makes deleted and added rows easier to inspect in code snippets, server logs, CSV rows, and structured text files.

Use word diff for small edits

Word-level comparison helps catch subtle wording changes in paragraphs, emails, essays, and policy text. It is especially helpful when most of the sentence stayed the same.

Compare text.Spot differences instantly.