JSON Formatter
Free online JSON formatter and validator. Beautify, minify, or validate your JSON data with ease. Features tree-view navigation, type detection, syntax highlighting, and error pinpointing. Supports large files and nested structures. Copy formatted output with one click. All processing happens in your browser — your data never leaves your device.
Formatted output will appear here
How to Format JSON Online
Format, validate, or minify your JSON data in seconds — no signup required.
Paste your JSON
Paste your raw JSON data into the input editor on the left side, or click the 'Paste' button to paste from your clipboard.
Choose an action
Select Prettify to format with indentation (2 or 4 spaces), Minify to remove whitespace, or Validate to check syntax.
View the result
The formatted output appears instantly in the right panel with syntax highlighting. Stats show key count, nesting depth, and file size.
Copy the output
Click the 'Copy' button to copy the formatted JSON to your clipboard, ready to use in your code or API.
What Is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. It is easy for humans to read and write, and easy for machines to parse and generate. JSON is the most common format for APIs, configuration files, and data storage across the web.
Valid JSON uses key-value pairs enclosed in curly braces for objects and square brackets for arrays. Keys must be strings wrapped in double quotes. Values can be strings, numbers, booleans, null, objects, or arrays. A common source of errors is trailing commas, single quotes, or unquoted keys — all of which this validator catches instantly.
Whether you're debugging an API response, editing a package.json file, working with configuration files, or preparing test data, a reliable JSON formatter saves time and prevents syntax errors before they reach production.
Frequently Asked Questions
What is a JSON formatter?
A JSON formatter is a tool that takes raw or minified JSON data and reformats it with proper indentation, line breaks, and spacing to make it human-readable. It can also validate JSON syntax, minify it for production use, and highlight errors in malformed data.
Is this JSON formatter free?
Yes, this JSON formatter is 100% free with no usage limits, no account required, and no ads. You can format, validate, and minify as much JSON as you need.
Is my JSON data safe?
Absolutely. All processing happens entirely in your browser — your JSON data never leaves your device. No data is sent to any server, making it safe for sensitive API keys, configuration files, and private data.
What's the difference between prettify and minify?
Prettify (or beautify) adds indentation and line breaks to make JSON readable by humans. Minify removes all unnecessary whitespace to reduce file size, which is ideal for production use and API responses.
Can I validate JSON without formatting it?
Yes. Use the Validate tab to check your JSON syntax without changing the formatting. The validator will pinpoint the exact location of any syntax errors.
What is the maximum JSON file size supported?
Since processing happens in your browser, the limit depends on your device's memory. Most modern browsers handle JSON files up to 50MB+ without issues.