JSON Formatter & Validator

How to use the JSON Formatter & Validator

1. Paste your JSON into the input box, or press “Load example” to try a sample.
2. Choose an indentation (2 spaces, 4 spaces or tab) and, if you want, sort keys alphabetically.
3. Press Format to pretty-print, Minify to remove all whitespace, or Validate to check syntax only.
4. If the JSON is invalid, the error shows the line and column to fix. Otherwise copy or download the result.

Good to know

• Validation uses the browser's built-in JSON.parse, so it follows strict RFC 8259 JSON: no comments, no trailing commas, no single quotes, no NaN or Infinity.
• Numbers are parsed as JavaScript numbers. Integers beyond 9,007,199,254,740,991 (2^53 − 1) lose precision when re-serialised, and duplicate object keys keep only the last value.
• Input is limited to 2,000,000 characters. Extremely deep nesting is reported as an error instead of freezing the page.
• Error positions come from your browser. Browsers that do not report a position (some versions of Safari) show the message without a line number.

Examples

Pretty-print a compact payload

{"id":7,"tags":["a","b"]} → formatted over several lines with your chosen indentation.

Find a syntax error

{"name": "Ada",} → Error with the line and column of the trailing comma, which standard JSON does not allow.

Minify for transport

A 4-space formatted object becomes one line with no spaces between tokens.

Frequently asked questions