Free Online JSON Formatter & Validator

How to use the JSON formatter

Paste your JSON into the input panel and choose Format JSON to create an indented, readable version. The formatter validates the content as it parses it, then shows the result in the output panel. Use Minify when you need compact JSON without extra whitespace. Copy the finished output when you are ready to use it elsewhere, or clear both panels to start again.

What is JSON and why format it?

JSON, short for JavaScript Object Notation, is a compact text format for representing structured data. APIs, configuration files, and applications often use it to exchange objects, lists, strings, numbers, booleans, and null values. Minified JSON is efficient to transmit, but long lines are difficult to inspect. Formatting adds indentation and line breaks so nested data is easier to scan, compare, and debug.

This online JSON formatter runs in your browser. Your pasted text is parsed locally by the browser's built-in JSON support; the formatting action does not send the content to a server. That makes it useful for inspecting sample responses and other snippets while keeping the workflow simple. Avoid sharing sensitive material in any online service unless you have checked its handling practices.

Common JSON syntax errors

JSON follows a stricter syntax than JavaScript object literals. Property names and string values need double quotes. A trailing comma after the final item in an object or array is invalid, and comments are not part of standard JSON. Values must use the exact lowercase forms true, false, or null. When parsing fails, the browser reports an error that often points near the unexpected character. Check the surrounding quotes, commas, and brackets first.

Quick examples

• Use {"name": "Ari"} rather than {name: 'Ari'}.
• Remove the comma after the last property or array value.
• Match every opening brace and bracket with a closing one.
• Escape quotation marks inside strings with a backslash.

Frequently asked questions