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How to Format and Validate JSON in the Browser
Use the JSON Formatter to format valid JSON, check parsing errors, minify output, and copy or download the result.
Open the JSON Formatter and paste a JSON value into the input panel. Select an indentation option, then use Format to parse the input with the browser's JSON parser and display formatted output. If the input is not valid JSON, the tool shows a validation error instead of producing formatted output.
Use Minify when you need the same valid JSON without extra whitespace. The tool also provides copy and download controls for the current output, plus a file picker for loading JSON from a local file. These operations are implemented in the browser: formatting and minifying use JSON.parse and JSON.stringify, and file loading uses the browser FileReader API.
Keep in mind that JSON requires double-quoted property names and string values. If the source is JavaScript object syntax, comments, or otherwise invalid JSON, correct it before formatting.