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JSON formatter & validator
Format, validate and minify JSON online for free. Two-space indentation, copy to clipboard and local processing in your browser.
Paste JSON, then choose Format, Minify or Validate.
Your input stays in this page’s memory. This tool does not upload it or save it in browser storage. Copy or export important input before leaving; work may be lost when the page is closed or reloaded.
Format JSON without changing its values
- Paste a JSON object, array or other valid JSON value into the editor.
- Choose Format JSON for two-space indentation, or Minify to remove whitespace outside strings.
- Use Validate to check syntax without changing the input, then Copy the result.
Numbers and duplicate keys
The formatter preserves number text, including large integers, decimal precision and exponent notation. It also preserves duplicate keys; it does not resolve them or verify an application’s data schema. Different consumers may interpret duplicate keys differently.
Invalid JSON and limits
Comments, trailing commas and unquoted keys are not valid JSON. Errors leave your input unchanged. The editor accepts up to two million characters and 200 levels of nesting. Never paste data that you are not permitted to process on this device.