JSON Formatter & Validator
Prettify, minify, and validate JSON — instant, in-browser.
What is JSON and why format it?
JSON (JavaScript Object Notation) is the universal data interchange format for APIs, configuration files, and structured data. Raw JSON from an API response is often minified — all on one line with no indentation — making it hard to read. Prettifying adds consistent indentation so the nesting structure is immediately visible. Minifying does the reverse: it removes all whitespace to produce the smallest possible file size for production use.
How validation works
The tool uses the browser's native JSON.parse()to validate your input. If the JSON is malformed, you'll see an exact error message pointing to the issue — for example, a missing bracket, an unquoted key, or a trailing comma. Fix the issue and click the format button again.
Frequently asked questions
Does formatting preserve key order?
Yes. JSON.stringify preserves the insertion order of object keys as they appear in your input, so your formatted output will have the same key sequence as the original.
Can I use 2-space or 4-space indentation?
Both options are available. Two spaces is the convention in most JavaScript and Node.js projects. Four spaces is common in Java, Python, and many other ecosystems. Pick whichever matches your team's style guide.
Is my JSON data kept private?
Yes. Formatting is done entirely in your browser using JavaScript. Nothing is sent to a server. Safe for sensitive config data, API responses, and internal documents.
