JSON Formatter & Validator
Format, minify, and validate JSON with instant error detection. Paste any JSON and get clean, readable output.
About the JSON Formatter
JSON is supposed to be readable. The version that comes back from most APIs isn't. This tool turns minified payloads into something a human can read, strips whitespace back out when you need a compact string, and tells you exactly what's wrong when something won't parse.
Paste your JSON and click Format. You get a clean indented block (2-space or 4-space, your call) with the key count, line count, and byte size shown right below it. That last one matters more than people expect — it's easy to forget how much a formatted payload weighs vs. its minified version. Minify does the reverse: down to the smallest valid string. And Validate tells you straight: does this parse? If not, the error message gives the exact position of the problem. No scrolling through 200 lines hunting for a trailing comma.
Where you'll use it
Inspecting API responses. Cleaning up package.json or tsconfig.json that have gotten messy. Preparing payloads for Postman or curl. Debugging why your app throws a parse error when the config looks fine. Minifying before committing so JSON diffs are actually readable.
Pro Tip
The most common parse errors are trailing commas after the last item in an array or object, single quotes instead of double quotes, and unquoted property keys. The error message points to the exact line and character, so you don't have to scan the whole thing manually.
JSON Beautifier, Pretty Printer, and Formatter — What's the Difference?
These terms describe the same operation. A JSON beautifier adds whitespace and indentation. A JSON pretty printer does the same with styled output. A JSON formatter is the umbrella term. Online, you'll also see "format JSON", "JSON viewer", and "JSON editor online" — they all solve the same problem. This tool covers all three modes in one place: beautify, minify, and validate — with byte-size output so you know exactly what your payloads weigh before and after.
Format vs. Minify vs. Validate
Format
Adds indentation and line breaks for readability. Use when reading, debugging, or code-reviewing. Choose 2-space or 4-space indent.
Minify
Strips all whitespace to the smallest valid string. Use for API payloads, fixtures, or configs where whitespace is pure overhead.
Validate
Runs a strict parse check and reports the exact position of any error. Use when you just need a yes/no on whether it will parse.
Works With Any JSON
API responses, package.json, tsconfig.json, environment configs, test fixtures, webhook payloads. Paste it in and the online JSON formatter handles the rest. All processing runs in your browser — nothing is sent to a server and there's no file size limit.