JSON Formatter & Validator
Paste JSON below to pretty-print it with proper indentation, minify it to a single line, or check it for syntax errors. Everything runs locally in your browser — your data never leaves your machine.
Frequently asked questions
Is it safe to paste sensitive JSON here?
Yes. This tool runs entirely in your browser using JavaScript — the JSON you paste is never uploaded to a server, logged, or stored.
Why is my JSON invalid?
The most common causes are trailing commas after the last item, single quotes instead of double quotes, unquoted property names, and comments (standard JSON does not allow comments). The error message shows where parsing failed.
What is the difference between formatting and minifying?
Formatting (pretty-printing) adds line breaks and indentation so the structure is easy to read. Minifying removes all unnecessary whitespace to make the file as small as possible for transfer or storage.