Beautify, minify, and validate JSON instantly — 100% client-side. Your data never leaves the browser.
// updated April 2026This JSON Formatter lets you instantly beautify and validate any JSON data. It runs entirely in your browser — no data is ever sent to a server, making it safe for sensitive configs, API responses, and tokens.
Features:
JSON (JavaScript Object Notation) formatting — also called "pretty printing" — adds indentation and line breaks to make compact JSON human-readable. For example, {"a":1,"b":2} becomes a structured, indented block.
JSON minification does the reverse — stripping all whitespace to reduce file size for production use or API payloads. Read more in our guide to formatting JSON and JSON validation guide.
Trailing commas — JSON does not allow a comma after the last item in an array or object. This is the most common error.
Single quotes — JSON requires double quotes for strings and keys. Single quotes are not valid.
Unescaped characters — special characters like backslash or newline must be escaped. See our guide to fixing invalid JSON.
JSON.stringify(obj, null, 2) — the third argument sets the indent size. To parse and reformat a JSON string: JSON.stringify(JSON.parse(jsonString), null, 2). Read the full guide: validate and format JSON in JavaScript.