JSON Formatter & Beautifier

Prettify your minified JSON instantly. Syntax highlighting, error validation, and proper indentation online.

Free Online JSON Formatter

Cleaning up minified JSON data is essential for debugging APIs and configuration files. Our formatter automatically indents keys, arrays, and objects to make them readable.

Smart Indent

Automatically structures nested objects and arrays with clear 2-space or 4-space indentation.

Syntax Check

Validates your input before formatting. If there's an error (like a missing comma), we'll let you know.

Secure

Your data never leaves your browser. All formatting happens client-side securely.

Why Format JSON?

JSON (JavaScript Object Notation) is often minified (compressed) to save bandwidth. While machines read this easily, humans struggle. Formatting restores the structure.

  • API Debugging

    Inspect complex API responses to verify fields.

  • Config Files

    Edit VS Code or server configs without breaking syntax.

Technical Details

JSON Syntax

JSON supports Objects `{}`, Arrays `[]`, Strings `""`, Numbers, Booleans, and Null. Keys must always be double-quoted strings unlike JavaScript objects. Not respecting this results in syntax errors.

Validation vs. Parsing

Our tool performs a strict parse using the browser's native `JSON.parse()`. If this fails, the input is invalid and cannot be formatted. This is stricter than some loose evaluators but ensures correctness.

Pretty Printing

We use standard recursive logic to insert newlines and 2-space indentation depth for every nested Object or Array. This transforms a single-line string into a human-readable tree.

Easy Steps

1

Paste Data

Paste your messy/minified JSON string.

2

Auto-Format

The tool automatically detects and beautifies the code.

3

Copy

Grab the clean JSON for your project.