JSON Formatter, Validator & Beautifier
Paste JSON, get it formatted, validated, and ready to copy — with errors pinpointed by position.
About this tool
WRRK's JSON formatter is a fast, browser-only tool for formatting, validating, beautifying, and minifying JSON. Paste raw JSON in, click Format, and get clean indented output. If the JSON is invalid, you get the exact position where the parser failed plus a human-readable explanation.
Everything runs locally in your browser. Your JSON never leaves your device, which matters when you're debugging API responses with auth tokens, customer data, or production payloads.
Use cases
- Reading API responses pasted from Postman or curl
- Debugging JSON config files (package.json, tsconfig.json, etc.)
- Validating webhook payloads before sending them
- Minifying JSON for embedding in HTML data attributes
- Cleaning up log output that has JSON lines mixed with text
- Inspecting JWT payload contents (the middle part is JSON)
Frequently asked questions
+−How do I format JSON online for free?
Paste your JSON into the formatter, click Format, and download or copy the cleaned-up version. It's free, has no character limit, and runs entirely in your browser.
+−What's the difference between formatting and minifying JSON?
Formatting (also called beautifying) adds indentation and line breaks for readability. Minifying strips all whitespace to make the file as small as possible — useful for config files and API payloads where size matters.
+−How do I validate if JSON is valid?
Paste it into the formatter — if it's invalid, you'll see a red error with the position where parsing failed, plus a description like 'expected comma' or 'unterminated string.'
+−Why does my JSON have a 'Unexpected token' error?
Common causes: trailing comma after the last item, single quotes instead of double quotes, unescaped quotes in strings, or missing closing brackets. The error position tells you exactly where to look.
+−Is my JSON data sent to a server?
No. The formatter runs entirely in your browser — your data never leaves your device. Safe for debugging payloads with API keys, tokens, or sensitive customer data.
+−How do I minify JSON for production?
Paste formatted JSON, click Minify, and you get a single-line compact version with all whitespace removed. Useful for config files and reducing API payload size.