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JSON Formatter & Validator

Format messy JSON into readable, indented text, validate it for syntax errors, or minify it down to a single line. Everything runs in your browser, nothing is uploaded anywhere.

What Is a JSON Formatter?

A JSON formatter takes JSON text and rewrites it with consistent indentation and line breaks, so nested objects and arrays are easy to read. Raw JSON from an API response or a minified file is often a single dense line, and reading it without formatting is slow and error-prone.

How to Format JSON Online

1. Paste your JSON into the box above.
2. Click Format to beautify it with proper indentation.
3. Copy the result or download it as a file.

JSON Formatter vs JSON Validator

Formatting changes how the JSON looks, adding indentation and spacing without changing its meaning. Validating checks whether the JSON is actually well-formed according to the JSON specification. This tool does both: Format will fail with a clear error if the JSON isn't valid, and Validate checks syntax without changing the text at all.

How to Fix Invalid JSON

Most JSON errors come down to a handful of common mistakes:

• Missing commas between properties or array items.
• Missing quotes around property names or string values. JSON requires double quotes, not single quotes.
• Unclosed braces { } around an object.
• Unclosed brackets [ ] around an array.
• Invalid values, such as a trailing comma after the last item, or undefined where a value is expected.

When validation fails, this tool points to the line and column where the parser gave up, which is usually right at or just after the actual mistake.