JSON Formatter & Validator
Paste JSON to pretty-print it with syntax highlighting, or minify it to a single line. Invalid input is caught instantly with the line and column of the problem. Nothing is uploaded — it all runs on your device.
JSON tool
About this JSON formatter
This is a JSON beautifier, validator, and minifier in one. Paste raw JSON into the input and it is parsed and re-rendered with color-coded keys, strings, numbers, booleans, and null. Use Format to indent it for reading, or Minify to strip every space and newline for the smallest possible payload — handy before pasting into a config file or a URL.
How to use it
- Paste or type JSON into the input panel — formatting happens as you type.
- Pick a 2-space, 4-space, or tab indent to match your project's style.
- If the JSON is malformed, the status turns to Invalid and the message shows what broke and where (line and column).
- Click Copy to grab the formatted output, or Minify for a one-line version.
Is my data private?
Yes. The parser is plain JavaScript running in your browser. Your JSON never leaves the page — there is no server, no upload, and no logging of what you paste.
What counts as valid JSON?
Strict JSON: double-quoted keys and strings, no trailing commas, no comments, and no single quotes. If you paste a JavaScript object literal it may be rejected — the error message will point you to the first character that breaks the rules.
Why does minify make the size smaller?
Minifying removes all insignificant whitespace — indentation, line breaks, and the spaces after colons and commas. The data is identical; only the formatting bytes are dropped, which matters for network payloads.
Does it handle large files?
It handles anything your browser can hold in memory, which is typically several megabytes without trouble. Very large inputs may take a moment to highlight.