Monu Tools

JSON Formatter & Validator

Format, beautify and validate JSON online with clear error messages for invalid input.

How to use the JSON Formatter

  1. 01

    Paste or type your JSON into the input panel.

  2. 02

    Press Run to parse and re-print it with a 2-space indent.

  3. 03

    Copy the formatted JSON, or read the error if the input is invalid.

Frequently asked questions

What does the JSON formatter do?

It parses your JSON, checks that it is valid, and re-prints it with a clean 2-space indent so it is easy to read. Invalid JSON returns a precise error message instead.

Is my JSON sent anywhere?

Your input is sent to our server only to format it and is returned immediately. It is not stored, logged or shared.

Why does it say my JSON is invalid?

The formatter follows the strict JSON standard: keys and strings need double quotes, no trailing commas and no comments. The error message shows where parsing failed.

About this tool

The JSON Formatter & Validator turns minified or messy JSON into a clean, indented structure you can actually read, and flags syntax errors with their exact position.

It is handy for inspecting API responses, debugging config files or tidying data before you commit it. Everything runs through a strict parser, so a successful format also confirms your JSON is valid.

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