JSON Formatter & Validator

Format, validate, and minify JSON data instantly. Identifies syntax errors and beautifies JSON with proper indentation.

Invalid JSON
Input JSON
0 chars
Output
0 chars
Valid JSON — 0 top-level keys

About JSON Formatter & Validator

Format, validate, and minify JSON data instantly using our free JSON formatter. Identify syntax errors, beautify nested structures with proper indentation, and minify JSON for compact storage or transmission.

What is JSON Formatting?

JSON formatting (also called JSON beautification) takes compact or poorly indented JSON and adds consistent indentation and line breaks to make it readable. Validation checks that the JSON follows the correct syntax and highlights any errors.

Features

  • Instant JSON validation with detailed error messages
  • Beautify JSON with 2-space indentation
  • Minify JSON to a single compact line
  • Key and item count displayed for valid JSON
  • One-click copy of formatted or minified output
  • No software installation required
  • Works entirely in your browser

Common Use Cases

  • Debug API responses and REST payloads
  • Validate JSON configuration files
  • Format JSON for human readability
  • Minify JSON before embedding in code
  • Check for syntax errors in data files

Why Use This JSON Formatter?

Quickly format and validate JSON in your browser without installing tools or pasting data into untrusted external services.

Frequently Asked Questions

Validation checks that your JSON follows correct syntax including properly matched brackets and braces, quoted keys, valid value types, and no trailing commas. Any error is shown with a message indicating the exact location of the problem.

Formatting adds indentation and line breaks to make JSON easy for humans to read. Minifying removes all whitespace to produce the most compact version suitable for storage or network transmission.

No. Formatting and validation run entirely in your browser with JavaScript. Your data is never uploaded or stored anywhere outside your current browser session.

Common causes include trailing commas after the last item in an array or object, unquoted keys, single quotes instead of double quotes, or mismatched brackets. The error message shows the position of the first problem found.

The formatter uses 2-space indentation which is the most widely adopted standard for JSON readability. This matches the default output of JSON.stringify in JavaScript and most popular editors.