💻 Developer Tools

{ } JSON Formatter

Minified or poorly-formatted JSON — a single unbroken line from an API response or log file — is nearly impossible to read by eye, and a single misplaced comma or bracket can make an entire payload invalid without an obvious clue as to where. This tool formats (pretty-prints) JSON with proper indentation, minifies it back down to a single compact line, and validates it, pointing out exactly what's wrong if it doesn't parse.

It's a daily utility for developers inspecting API responses, debugging config files, or cleaning up JSON before sharing it in documentation or a bug report.

JSON input

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How to use the JSON Formatter

Paste your JSON into the input box.
Click Format to pretty-print it with indentation, or Minify to compact it to one line.
If the JSON is invalid, an error message will point to the problem so you can fix it.

How formatting and validation work

The tool parses your input using the standard JSON parser, which strictly enforces the JSON specification — double-quoted keys and strings, no trailing commas, and valid nesting of objects and arrays. If parsing fails, the browser's own error message (which includes the position where parsing broke) is shown to help you locate the issue. On success, the parsed structure is re-serialized either with indentation (format) or without any extra whitespace (minify).

Frequently asked questions

Why is my JSON showing as invalid when it looks fine?

Common causes include trailing commas after the last item in an object or array, single quotes instead of double quotes around strings and keys, unquoted keys, or a missing closing bracket. JSON is stricter than JavaScript object literal syntax, so code that looks valid as JS can still be invalid JSON.

What's the difference between formatting and minifying?

Formatting adds indentation and line breaks to make JSON easy to read by eye. Minifying strips all unnecessary whitespace to produce the smallest possible payload size — useful for reducing bandwidth in API responses, though it's much harder to read.

Is my JSON data uploaded anywhere?

No — parsing, formatting and validation all happen locally in your browser using JavaScript's built-in JSON parser. Nothing you paste is sent to a server, so it's safe to use with sensitive API payloads or internal config files.