JSON Formatter & Validator
Paste raw JSON to validate it, prettify it with proper indentation, minify it for transport, or copy the clean result.
Formatted output appears here.100% private
This tool runs entirely in your browser. Nothing you type is uploaded, logged or stored.
JSON Syntax Validation and API Debugging
JSON is strict: keys must be double-quoted strings, trailing commas are illegal, comments are not allowed, and only double quotes delimit strings. Most API bugs labelled “server error” are really malformed payloads — a stray comma after the last array item, a single-quoted key copied from JavaScript, or an unescaped newline inside a string value.
Validating before you send saves round trips. Prettified JSON with two-space indentation makes nesting depth obvious, which is how you spot an object that should have been an array or a field buried one level too deep. Minified JSON strips all insignificant whitespace and is what you want in request bodies, config files shipped to clients and log lines, where every byte counts. When debugging a failing endpoint, format the request payload and the response side by side: mismatched types (a number sent as a string, null instead of an empty array) become visible instantly.
Frequently asked questions
It runs the native JSON parser and reports the exact error message and position when the document is invalid, so you can jump straight to the offending character.