Free JSON formatter, validator and minifier

This free online JSON formatter beautifies, validates, and minifies JSON in your browser, highlighting syntax errors instantly and showing payload size.

• Format (pretty-print) JSON with custom indentation.
• Validate JSON and see the exact syntax error.
• Minify JSON to a compact single line.
• Copy or export the cleaned JSON.

Frequently asked questions

How do I validate JSON online?

Paste your JSON into the Black Hoodie Dev JSON formatter. It validates as you type and points out syntax errors such as missing commas or quotes.

How do I minify JSON?

Paste your JSON and choose Minify to strip whitespace and produce compact single-line JSON.

Is my JSON sent to a server?

No. Formatting and validation run entirely in your browser.