Free JSON Formatter & Validator Online – Beautify, Validate & Minify JSON

Messy, unindented JSON from an API response or a config file is hard to read and even harder to debug. A free online JSON formatter instantly beautifies your code, catches syntax errors, and lets you minify it back down for production — all without installing anything.

What it does

• Beautify — turns a single-line JSON blob into clean, indented, readable code.
• Validate — instantly flags missing commas, brackets, or quotes with a clear error message.
• Minify — strips all whitespace to produce the smallest possible file size for production use.
• Tree view — collapse and expand nested objects and arrays to navigate large JSON files easily.

How to format JSON online

1. Paste your raw JSON into the input box.
2. The tool automatically validates and beautifies it as you type.
3. If there's a syntax error, it's highlighted with the exact line and reason.
4. Copy the formatted result, or switch to minify mode before copying.

Who uses it

• Developers debugging API responses or configuration files.
• Students learning to work with JSON data structures.
• Anyone who needs to quickly check if a JSON file is valid before using it.

All formatting and validation happens locally in your browser — your data, API keys, or configuration files are never uploaded to a server. Free, fast, and private.

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