JSON Formatter & Validator

Paste JSON to validate, pretty-print or minify it. Your data never leaves your browser.

About this JSON validator

JSON (JavaScript Object Notation) is the most common format for APIs and configuration files. A single missing comma or quote makes a JSON document invalid. This tool parses your input with the browser's strict JSON parser and points to the exact line and column of the first error.

Common JSON errors

  • Trailing commas – [1, 2, ] is not allowed.
  • Single quotes – strings and keys must use double quotes.
  • Unquoted keys – {name: 1} must be {"name": 1}.
  • Comments – standard JSON does not support // or /* */.

Is my data safe?

Yes. Formatting and validation happen entirely in JavaScript on your device. Nothing is uploaded or stored.

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