JSON Formatter & Validator

Beautify, validate and minify JSON with syntax highlighting. Everything runs in your browser — your data is never sent anywhere and nothing is stored.

More PAYATE tools

Bulk GeneratorBulk cards + CSV/JSON/XML export IBAN ValidatorValidate & generate test IBANs Base64 Encode/DecodeConvert text to/from Base64 Visa GeneratorFormatted Visa test numbers

Frequently asked questions

What does this tool do?

It formats (beautifies), minifies and validates JSON. Paste JSON to pretty-print it with indentation and colour, collapse it to one compact line, or check that it is valid and see exactly where an error is.

Is my JSON sent anywhere?

No. Everything runs in your browser with JavaScript — your JSON is never uploaded to a server and nothing is stored. It is safe to paste data you would not want to transmit.

Why does it say my JSON is invalid?

Common causes are a trailing comma, single quotes instead of double quotes, missing quotes around keys, or an unclosed bracket or brace. The error message points to the position where parsing failed.

What is the difference between format and minify?

Format adds line breaks and indentation so JSON is easy to read. Minify removes all optional whitespace to make the smallest possible payload — useful for sending JSON over the network.

Does it support large files?

Yes, within your browser's memory. Very large documents (tens of MB) may be slow to highlight; minifying is always fast. Nothing is uploaded, so there is no size limit on the server side.