JSON Formatter

Format and validate JSON data. Free online tool to beautify, minify, and debug JSON strings instantly.

Input

JSON powers modern APIs, configuration files, and data pipelines. Raw payloads quickly become unreadable, so this formatter cleans them up, validates structure, and flags errors before they break deployments.

What is JSON Formatter?

The JSON Formatter is a browser-based inspector that pretty-prints objects, standardizes indentation, and validates structure in one click. Use it when you need to review webhook payloads, cloud policies, or exported analytics without opening an IDE.

How the JSON formatter works

The formatter parses your text with the browser's native JSON engine, which follows RFC 8259 strictly — it rejects trailing commas, single-quoted strings, comments, and unquoted keys, the four things that break most hand-edited JSON. Once parsed, the value is re-serialized with your chosen indentation, so the output is guaranteed to be valid, canonical JSON rather than merely re-spaced text. If parsing fails, the error message reports the position of the first invalid token so you can jump straight to the problem. Nothing is uploaded; the parse happens entirely in your browser.

Features

Live validation: Highlights mismatched braces, quotes, and duplicated keys as you work.
Error hints: Shows descriptive messages with line numbers so you can fix issues faster.
Pretty print: Expands nested arrays and objects with consistent indentation for readability.
Minify and share: Removes whitespace for payloads that need to be embedded into scripts or URLs.

How to Use

1

Paste or upload: Drop JSON from cURL responses, config files, or logs into the editor.

2

Choose indentation: Select 2 spaces, 4 spaces, or tabs to match your style guide.

3

Run formatter: Click Run Tool to prettify and validate; syntax issues include line numbers for quick fixing.

4

Copy or minify: Copy the readable output or grab the compact minified version for production scripts.

Common Mistakes

Trailing commas: JSON does not allow commas after the last item in an object or array.
Single quotes: Keys and strings must always use double quotes.
Comments or stray values: Remove // comments and loose values that sit outside objects or arrays.

Examples

API debugging: Inspect webhook or REST responses to confirm nested data before integrating.
Config review: Clean up package.json, .well-known files, or IAM policies prior to deployment.
Data cleaning: Spot inconsistent property names or array contents in exported analytics files.

See also

  • CSV to JSON — Starting from a spreadsheet export? Convert CSV to JSON first, then format it here.
  • Base64 Encoder — Embedding JSON in a data URI or token? Base64-encode the formatted output.

FAQ

Is my JSON data sent to a server?

No, all processing happens locally in your browser. Your data never leaves your device.

Can I format invalid JSON?

The tool will attempt to highlight errors, but it requires valid JSON syntax to format correctly.

How large can my JSON file be?

Most browsers handle payloads of a few megabytes without trouble. Extremely large files may feel slow, so trim logs before formatting when possible.