JSON Formatter & Viewer
Format, validate, and view JSON data with syntax highlighting. Pretty-print minified JSON, expand/collapse nested objects, and catch errors instantly. All processing happens in your browser for complete privacy.
Our free JSON Formatter & Viewer helps developers and data professionals instantly format, validate, and explore JSON data. Paste your minified or messy JSON and get beautifully formatted output with syntax highlighting. The interactive tree view lets you expand and collapse nested objects for easy navigation. Perfect for debugging APIs, working with configuration files, or analyzing data structures. 100% client-side processing means your data never leaves your browser, ensuring complete privacy and security. No signup required, no data stored, no limits.
Enter valid JSON to see formatted output
Your Data Stays Private
All JSON processing happens directly in your browser. Your data is never sent to any server, stored, or logged. You can even use this tool offline after the page loads.
How to Use the JSON Formatter
- Paste your JSON into the input textarea on the left. You can paste minified, unformatted, or messy JSON data.
- View the formatted output instantly on the right panel with proper indentation and syntax highlighting.
- Switch to Tree View to explore nested objects and arrays interactively. Click on any object or array to expand or collapse it.
- Copy the formatted JSON using the "Copy Formatted" button to use it in your code, documentation, or share with colleagues.
- Fix errors if the validator detects invalid JSON. The error message will tell you exactly what went wrong.
Features
Pretty Print
Automatically formats JSON with proper indentation
Syntax Highlighting
Color-coded keys, strings, numbers, and booleans
Tree View
Interactive expand/collapse for nested structures
Real-time Validation
Instant feedback on JSON syntax errors
One-Click Copy
Copy formatted JSON to clipboard instantly
Privacy First
100% client-side, no server processing
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Frequently Asked Questions
What is JSON and why do I need to format it?▼
JSON (JavaScript Object Notation) is a lightweight data format used for storing and exchanging data between servers and applications. Raw JSON is often minified (compressed without spaces or line breaks) to reduce file size. Formatting makes it human-readable with proper indentation, making it easier to understand, debug, and edit.
Is my data safe when using this tool?▼
Yes, absolutely. This JSON formatter runs entirely in your browser using JavaScript. Your data never leaves your computer and is not sent to any server. There's no backend processing, no logging, and no data storage. Once you close or refresh the page, your data is gone. You can even disconnect from the internet and the tool will continue to work.
What does "Invalid JSON" error mean?▼
JSON has strict syntax rules. Common errors include: missing or extra commas, unquoted keys (keys must be in double quotes), single quotes instead of double quotes, trailing commas after the last item, and unescaped special characters. The error message will indicate where the parser encountered the problem.
Can I format large JSON files?▼
Yes, this tool can handle reasonably large JSON data. However, extremely large files (several megabytes) may cause your browser to slow down since all processing happens locally. For very large files, consider using a desktop JSON editor or splitting the data into smaller chunks.
What's the difference between Formatted and Tree View?▼
Formatted View shows the JSON as text with syntax highlighting and proper indentation - perfect for copying and pasting into code. Tree Viewdisplays the JSON as an interactive, collapsible structure where you can expand and collapse nested objects and arrays - ideal for exploring complex data.
Frequently Asked Questions
❓ Is this tool free?
Yes! All our tools are completely free. No registration, no hidden charges, no ads. Just open and use.
🔒 Is my data safe?
Absolutely. All calculations happen in your browser. We don't store, send, or track any of your data. Everything is processed locally on your device.
📱 Can I use this on mobile?
Yes! All our tools are fully responsive and work perfectly on smartphones, tablets, and desktops.
🌐 Do I need internet?
No! Once the page loads, you can use the tool completely offline. All calculations happen in your browser without any server connection.