JSON Formatter & Validator
Pretty-print, validate, and minify JSON — with syntax coloring and instant error reporting.
Free · No sign-up · Runs in your browser
How to use
- Paste raw or minified JSON into the input.
- Click Format to pretty-print, or Minify to compact it.
- Errors are shown inline with the line and message.
- Copy the result or clear the form.
Questions
Does my JSON leave the browser?
No. Everything runs in JavaScript in your browser — your data is never uploaded.
What indentation is used?
Two spaces by default, following common style guides. The minified form strips all whitespace.
Can it validate JSON5 or JSONC (with comments)?
No. This tool validates strict RFC 8259 JSON. Comments and trailing commas are not allowed in standard JSON.
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