JSON Formatter, Validator & Minifier
Format, validate and minify JSON with clear error messages. Client-side.
π Runs entirely in your browser. Your input and output are never sent to a server or stored β fully private.
About this tool
This JSON formatter pretty-prints messy JSON with clean indentation, validates it and points to the line where any syntax error occurs, and can minify it back to a compact single line. Paste an API response or config, and instantly get readable, well-structured JSON you can copy. It works entirely in your browser, so even sensitive payloads stay on your device.
Frequently asked questions
Why does my JSON fail to validate?
The most common causes are a trailing comma after the last item, single quotes instead of double quotes around keys and strings, missing quotes on keys, or unescaped characters. The validator highlights where parsing breaks so you can jump straight to the problem.
What is the difference between formatting and minifying?
Formatting (or beautifying) adds line breaks and indentation to make JSON easy to read, while minifying removes all unnecessary whitespace to make the smallest possible payload. Use formatting while debugging and minifying to save bandwidth in production.
Is my JSON sent anywhere?
No. Your JSON is parsed and formatted locally in your browser, so API responses, tokens and other sensitive data are never sent to a server.