100% Free, Private, In-Browser Tool
No uploads. No accounts. No limits. Your files never leave your device.
JSON Formatter
Beautify, format, minify, and lint your JSON data in real-time. Upload a file or paste your code below.
The file will be read locally inside your browser. Max file size is 5MB.
Drag & drop a JSON file here, or click to browse
The file will be read locally inside your browser
Max file size: 5MB
Editor Mode
Empty
KNOWLEDGE BASE
Frequently Asked Questions
Everything you need to know about processing files securely in your browser
How does this offline JSON formatter prettify code?
This tool runs entirely in your browser using standard JavaScript. When you paste your raw JSON or upload a file, it parses it locally using JSON.parse and formats it with your selected indentation using JSON.stringify, without sending any data to a server.
Is my JSON data secure when using this tool?
Yes, 100% secure. All processing occurs locally on your device. Your sensitive data or API keys never leave your browser, making it completely private and offline-safe.
What is the difference between prettifying and minifying JSON?
Prettifying (or formatting) adds spacing, tabs, and line breaks to make JSON readable for developers. Minifying removes all unnecessary whitespace, comments, and newlines to reduce the payload size for faster network transmission.
Can this tool validate and lint broken JSON?
Yes, the tool automatically validates your JSON structure as you type. If there is a syntax error (like missing commas or unquoted keys), it displays a detailed linting error with the exact reason so you can debug the payload.