Free JSON Formatter
Paste minified or messy JSON and get clean, indented, readable output in one click. This free formatter validates your JSON as it formats — pinpointing exactly where errors are — and shows useful stats like depth, key count, and size, all privately in your browser.
Formatted JSON
Invalid JSON
How to Use the JSON Formatter
- Paste your JSON into the input box (minified or messy — either works).
- Choose your indentation: 2 spaces, 4 spaces, or tabs.
- Click Format JSON — valid JSON is beautified instantly.
- If there is an error, read the message with line position, fix it, and retry.
Features
Beyond pretty-printing, the formatter validates strictly with the browser’s JSON parser and extracts the error position from the message, showing you the offending line and a pointer to the exact character. A stats line reports type (object/array), total keys, nesting depth, and byte size — handy when auditing API responses.
Benefits & Use Cases
API developers paste raw responses here to actually read them; support engineers reformat customer payloads before analysis; students learn JSON structure by seeing nesting visually. Because parsing is local, bearer tokens and personal data inside payloads never leave your machine.
Tips
When an API returns an error blob on one line, format it here first — the structure usually reveals the problem immediately. Use the JSON validator for a strict validity verdict, or the minifier when you need the compact form for production.
Frequently Asked Questions
What does a JSON formatter do?
It takes compact or inconsistently spaced JSON and rewrites it with consistent indentation and line breaks, so nested objects and arrays are easy to read. The data itself is unchanged — only the layout improves.
How do I find an error in my JSON?
Paste it here and click Format. If the JSON is invalid, the tool shows the parser’s error message along with the line number and a pointer to the exact character where parsing failed.
What are the most common JSON errors?
Trailing commas, single quotes instead of double quotes, unquoted property names, comments, and missing or extra brackets. JSON is stricter than JavaScript object literals — this tool flags all of them.
Can I format very large JSON files?
Yes, within reason. The browser handles multi-megabyte payloads, though extremely large files (tens of MB) may take a few seconds. Everything stays local.
Is my JSON uploaded anywhere?
No. Parsing and formatting run entirely in your browser with JavaScript — your data never leaves your device.
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