JSON Formatter & Validator
Free online JSON formatter and validator. Beautify messy JSON, minify for production, or validate syntax with line-precise errors. Runs in your browser.
JSON Input
Output
Frequently asked questions
›Is my JSON sent to a server?
No. The formatter runs entirely in your browser — your data never leaves your device.
›What's the difference between Beautify and Minify?
Beautify adds whitespace and indentation for readability. Minify removes all unnecessary whitespace to reduce file size for transport.
›Why does Validate report an error?
JSON requires double-quoted keys, no trailing commas, and no comments. The error message shows the line and column to fix.
›Does it support JSON5 or JSONC?
No — strict JSON only (ECMA-404). Comments and trailing commas are common reasons for parse errors.
›How big a JSON can I paste?
Anything your browser can handle in memory — typically tens of megabytes. Very large files are best processed locally with jq or a script.
›Is the JSON formatter free?
Yes — completely free, no signup, no ads.