JSON Formatter & Validator
Paste JSON on the left. Format it, minify it, or catch what's broken — everything runs in your browser, and nothing is uploaded anywhere.
Format
Turns compact or messy JSON into readable, indented text with your choice of indent width.
Minify
Strips whitespace to shrink JSON for APIs, configs, or anywhere payload size matters.
Runs in your browser
Parsing happens on your device. Your JSON is never sent to a server or stored anywhere.
About this tool
A JSON formatter takes JSON text — often minified, copied from an API response, or pasted from a log file — and rewrites it with consistent indentation and line breaks so it's easy to read. A validator does the opposite check: it confirms the text is actually well-formed JSON before you rely on it, and tells you exactly where it breaks if it isn't.
Why does my JSON say it's invalid?
The most common causes are a trailing comma after the last item in an object or array, missing quotes around a key, single quotes instead of double quotes, or an unclosed bracket. This tool reports the exact line and column where parsing failed so you can jump straight to it.
What's the difference between formatting and minifying?
Formatting adds indentation and line breaks to make JSON readable for people. Minifying removes all of that extra whitespace, producing the smallest valid representation — useful when you're sending JSON over a network or storing it in a database column.
Is it safe to paste sensitive data here?
Yes. All formatting, validation, and minifying happens locally in your browser using JavaScript's built-in JSON parser. Nothing you type is sent to a server, logged, or stored.
What indent size should I use?
Two spaces is the most common convention in JSON and JavaScript codebases and keeps deeply nested objects compact. Four spaces can be easier to scan for shallow structures. Tabs work well if your editor is set up to display them at your preferred width.