JSON Validator & Beautifier

Check if your JSON is valid, get precise error locations, and format it cleanly — all in your browser.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data format based on key-value pairs. It’s the standard for APIs, config files, and data exchange.

Common errors

• Trailing commas (not allowed in JSON)
• Single quotes instead of double quotes
• Missing brackets or braces
• Comments (not allowed in pure JSON)

FAQ

Does JSON allow comments? No. If you need comments, use JSONC (VS Code-style) or a format like YAML.

Can JSON have trailing commas? No — strict JSON forbids them, though some parsers tolerate them.