Free Online JSON Formatter and Validator

Format JSON into readable, indented output, minify it for compact use, and validate syntax in your browser. Useful for developers, API responses, configuration files and data review.

Format or validate JSON

Paste JSON and choose an action.

This tool runs in your browser. Input content is not intentionally uploaded by this page.

How does a JSON formatter work?

JSON (JavaScript Object Notation) is a text format used to exchange structured data. A formatter parses the input and adds indentation and line breaks to make nested objects and arrays easier to read. Minification removes unnecessary formatting whitespace while preserving the parsed data structure.

How to use this JSON formatter

  1. Paste your JSON into the input area.
  2. Select Format JSON to add indentation, or Minify JSON to create compact output.
  3. Select Validate to check whether the input can be parsed as JSON.
  4. The formatted or minified result replaces the text in the input area. Use Copy JSON text to copy the current content.

Common JSON errors

  • Missing commas between properties or array items.
  • Unquoted property names or single-quoted strings.
  • Trailing commas before a closing brace or bracket.
  • Unescaped quotation marks or invalid escape sequences inside strings.

Frequently asked questions

Does formatting change the JSON data?

Formatting changes whitespace and indentation, not the parsed values. Minification also removes formatting whitespace; it should not change the JSON data structure.

Can I use this tool to validate JSON?

Yes. Select Validate to check whether the input is valid JSON syntax. A successful parse does not guarantee that the data matches a particular API schema.

Is my JSON uploaded?

The formatting and validation actions run in your browser. Avoid pasting confidential data into any online tool on a device or browser you do not trust.

What is the difference between JSON and JavaScript?

JSON is a data format with stricter syntax than JavaScript. For example, JSON requires double-quoted strings and property names and does not support comments or functions.

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