Paste JSON below to instantly format, validate, or minify it. Everything runs in your browser — nothing you enter here is uploaded, stored, or logged.
Your JSON is processed locally in your browser and is not uploaded to our server.
How to Use
- Paste or type your JSON into the input panel.
- Click Format / Beautify for readable, indented JSON, Minify for the smallest possible output, or Validate to just check correctness without changing the input.
- Use Copy Output or Download to take the result with you.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based format for representing structured data — objects, arrays, strings, numbers, booleans, and null values. It’s the most common format for exchanging data between a browser, a server, and APIs, because it’s easy for both humans and machines to read.
JSON Formatting vs Minification
Formatting (also called beautifying or pretty-printing) adds consistent indentation and line breaks so the structure is easy for a person to read — useful while writing, debugging, or reviewing JSON. Minification strips all unnecessary whitespace to produce the smallest possible file size — useful when sending JSON over a network or storing it, where readability doesn’t matter but every byte does.
Common JSON Errors
- Trailing commas — a comma after the last item in an object or array (
{"a": 1,}) is not valid JSON. - Unquoted keys — object keys must be wrapped in double quotes, e.g.
{"key": "value"}, not{key: "value"}. - Single quotes — JSON strings must use double quotes; single quotes aren’t valid.
- Mismatched brackets — every
{/[needs a matching}/]of the same type in the right order. - Comments — standard JSON has no comment syntax;
//or/* */will fail to parse.
FAQ
Is my JSON uploaded anywhere?
No. Formatting, validation, and minification all happen locally in your browser using native JavaScript. Your input is never sent to our server.
Why does it say my JSON is invalid?
The validator shows the reason it failed, and the approximate line and column where the problem starts when the browser can determine it. Check the Common JSON Errors section above for the usual causes.
Is there a size limit?
There’s no artificial limit, but very large input is bound by your browser’s own memory and performance, since everything runs client-side.
Do I need an account?
No. The tool is free to use and doesn’t require sign-up.