JSON Formatter & Validator
Format, validate and minify JSON instantly in your browser.
Formatted output will appear here.
What is a JSON Formatter?
A JSON formatter reformats raw JSON — often returned by an API in a single, unreadable line — into a properly indented structure. This makes it easier to spot the shape of your data, find missing commas or brackets, and understand nested objects and arrays at a glance.
How to format JSON online
Paste your JSON into the input panel above and click Format. The tool will pretty-print it with two-space indentation. If the JSON is invalid, you'll see a specific error instead of a blank output.
How to validate JSON
Click Validate to check the input without reformatting it. This is useful when you just want a quick pass/fail answer on whether a JSON payload is well-formed, such as before saving a configuration file or sending an API request body.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based data format used to exchange data between a server and a client, or between different parts of a system. It represents data as key-value pairs, arrays, strings, numbers, booleans and null.
JSON Formatter vs JSON Validator
Formatting changes how the JSON looks (indentation and spacing) without changing its meaning. Validation only checks whether the JSON is syntactically correct — it doesn't alter the input. This tool supports both from the same input.
Is my JSON uploaded?
No. Formatting, validating and minifying all happen locally in your browser using the JavaScript JSON parser. Your data is never sent to a server.
Frequently asked questions
What is a JSON formatter?+
A JSON formatter takes compact or messy JSON text and rewrites it with consistent indentation and line breaks, making it much easier to read and debug.
Is this JSON formatter free?+
Yes. This tool is completely free to use, with no signup and no limits on everyday usage.
Is my JSON uploaded to a server?+
No. All formatting, validation and minifying happens locally in your browser using JavaScript's built-in JSON parser — your data never leaves your device.
Can I validate JSON with this tool?+
Yes. Click Validate to check whether your input is syntactically correct JSON, with a clear error message if it isn't.
Can I minify JSON?+
Yes. Click Minify to remove all unnecessary whitespace and produce the smallest possible valid JSON representation.
Can this tool handle large JSON files?+
Yes, within reason — since everything runs in your browser, very large files depend on your device's available memory rather than a server limit.