Is Diff Shuttle free?

Yes, Diff Shuttle is completely free with no hidden costs. All features can be used without limits and without creating an account.

Is my text uploaded to a server?

No. All processing in Diff Shuttle happens locally in your browser. Your text never leaves your device.

What file formats are supported?

Diff Shuttle supports plain text (.txt), JSON (.json), CSV (.csv), JavaScript (.js/.jsx), TypeScript (.ts/.tsx), Python (.py), HTML, CSS, Markdown, and many more formats.

What comparison modes are available?

Diff Shuttle offers five comparison modes: Text Diff (line-by-line), Word Diff, JSON Diff, CSV Diff, and Character Diff. Each mode is suited for different use cases.

Can I ignore whitespace or case when comparing?

Yes. Diff Shuttle provides 'Ignore Whitespace' and 'Ignore Case' options, allowing you to customize comparison behavior as needed.

How do I compare large files?

You can drag and drop files or use the 'Select File' button to upload. Diff Shuttle supports files up to 10MB. All processing happens in the browser, so larger files may take slightly longer to process.

Can I export comparison results?

Yes. Click the 'Export as Text' button to download the comparison result as a .txt file with all change markers and statistics.

What's the difference between Diff Shuttle and DiffChecker?

Diff Shuttle processes everything in the browser — no file uploads, 100% private. DiffChecker requires uploading files to servers. Diff Shuttle also supports more comparison modes (JSON, CSV, character) and is completely free with no ads.

Does it support both side-by-side and unified views?

Yes. Diff Shuttle supports both 'Side by Side' and 'Unified' view modes. Side-by-side shows changes left and right, while unified displays all changes in a single column.

About Diff Shuttle

A fast, private, browser-based text and code comparison tool by ShuttleLab

What is Diff Shuttle?

Diff Shuttle is a free online text and code comparison tool that processes everything directly in your browser. Unlike traditional diff tools that upload your files to remote servers, Diff Shuttle uses modern web technologies — JavaScript diff algorithms and the browser's rendering engine — to compare your texts without ever leaving your device.

Built by ShuttleLab, Diff Shuttle supports plain text, source code, JSON, and CSV comparison with intelligent algorithms that highlight additions, deletions, and modifications. Whether you need to review code changes, compare configuration files, or track document revisions, Diff Shuttle handles it all with zero privacy risk.

100% Private

All comparison happens locally in your browser. No files are uploaded, no data is collected, and no third parties can access your content.

No Account Required

Start comparing immediately — no sign-up, no email, no tracking. Just paste your text and go.

Multiple Formats

Compare plain text, source code, JSON, and CSV files with format-aware diff algorithms for accurate results.

Lightning Fast

Instant comparison powered by optimized JavaScript algorithms. No server round-trips, no waiting.

When should I use Diff Shuttle?

1Code review and pull requests

Before: Manual line-by-line code comparison, easy to miss subtle changes

After: All differences automatically highlighted — green for additions, red for deletions

2Configuration file version comparison

Before: Two config file versions — hard to quickly spot changed settings

After: JSON mode auto-formats and compares, pinpointing exactly which fields changed

3Document revision tracking

Before: Can't visually see what was specifically changed between document versions

After: Word diff mode precisely marks every modified word

4Data validation and CSV comparison

Before: Manually comparing large CSV files is nearly impossible

After: CSV mode compares by row, quickly revealing data differences

5Student assignment checking

Before: Teachers struggle to quickly assess similarity between assignments

After: Side-by-side comparison shows all differences, with a clear percentage of changes

How-To Guides

How to compare two texts

1Open the Diff Shuttle website (diff.shuttlelab.org)
2Paste your original text in the left 'Original' area, or drag-drop/select a file to upload
3Paste the modified text in the right 'Modified' area
4Click the 'Compare' button
5View the highlighted differences — green for additions, red for deletions

How to compare JSON files

1Select 'JSON Diff' as the comparison mode
2Paste or upload two JSON files
3Click compare — JSON is auto-formatted then structurally compared
4See which fields were added, removed, or modified

How to export comparison results

1After completing a text comparison
2Click the 'Export as Text' button in the control panel
3The diff result will download as a .txt file with all changes and statistics

Diff Shuttle vs Similar Tools (as of 2026-06)

Feature	Diff Shuttle	DiffChecker	Text-Compare
100% Local Processing	✓	✗	✗
No Registration Required	✓	✗	✓
JSON Diff	✓	Paid	✗
CSV Diff	✓	✗	✗
Word Diff	✓	✓	✗
Character Diff	✓	✗	✗
File Drag & Drop	✓	✓	✗
Export Results	✓	Paid	✗
Completely Free	✓	Free tier limited	✓

Frequently Asked Questions

Meeting you for the first time feels like the return of an old friend

Diff Shuttle is crafted with care by ShuttleLab — completely free. If it has helped you compare even a single text, sharing it with friends who need it is the best support we could ask for.

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Get in Touch

Have questions, feedback, or need support?

support@shuttlelab.org