Format, validate, and minify JSON instantly. Free, fast, and 100% client-side.
Free online JSON formatter, validator and minifier. Beautify or compact your JSON with one click. Runs in your browser, so your data never leaves your device.
No. The JSON formatter runs entirely in your browser using client-side JavaScript. Your data never leaves your device, which makes it safe to use even with sensitive payloads.
Formatting (beautifying) adds indentation and line breaks so the JSON is easy to read. Minifying removes all whitespace to produce the smallest possible string, which is useful for embedding JSON in URLs or reducing payload size.
Common mistakes are trailing commas, single quotes around strings or keys, unquoted keys, or using JavaScript-style comments. JSON is strict. Keys and strings must use double quotes and the last element cannot end with a comma.
Yes. The formatter is optimized to handle files up to several megabytes. For very large datasets you may want to use a command-line tool like jq for better performance.