JSON Formatter
Format, validate, and minify JSON with syntax highlighting.
Input
Output
How to use this tool
- Paste your JSON in the input area.
- Click 'Format' to prettify with proper indentation.
- Click 'Minify' to compress to a single line.
- Click 'Validate' to check if JSON is valid.
- Copy the output for use in your projects.
About this tool
JSON Formatter is an online, free tool that formats, validates, and minifies JSON data. No registration required! It prettifies messy JSON with proper indentation, minifies for production use, and validates syntax to catch errors. Essential for developers working with APIs, configuration files, and data interchange.
Frequently asked questions
How do I format messy JSON?
Paste it into the input area and click Format. The output is re-indented with consistent nesting so the structure is readable. If the JSON is invalid you get an error instead, which tells you the parse failed before you go looking for a logic bug.
What is the difference between formatting and minifying?
Formatting adds indentation and line breaks so a human can read the structure. Minifying strips every optional space and newline so the payload is as small as possible. Both describe exactly the same data; use formatted JSON while you are working and minified JSON when you are shipping it over a network.
Why does my JSON say it is invalid?
The usual culprits are a trailing comma after the last item in an object or array, single quotes instead of double quotes, unquoted keys, a missing closing brace, or a comment. JSON allows none of those, even though JavaScript object literals allow most of them.
Can JSON contain comments?
No. The specification has no comment syntax, which is why pasting a commented configuration file here fails to parse. Some tools accept a superset called JSONC; strip the comments before validating against strict JSON.
Does formatting change my data?
No. Only whitespace changes. Keys, values, ordering and types come through exactly as they were, so a formatted document is byte-for-byte equivalent to the original once whitespace is ignored.
Is my JSON sent to a server?
No. Parsing and formatting happen in your browser using the built-in JSON parser. Nothing is uploaded, stored or logged, which matters because API responses pasted into a formatter routinely contain tokens and personal data.