Completely safe. Everything runs in your browser with JavaScript. Nothing is sent to any server — paste API keys or sensitive data without worry.
What does beautify do?
Beautify adds consistent indentation and line breaks to make compact or minified JSON human-readable. It's the opposite of minify.
Why is my JSON invalid?
Common errors: trailing commas after the last item, single quotes instead of double quotes, unquoted keys, comments (JSON doesn't allow them), or undefined/NaN values.
What is the tree view?
Tree view shows JSON as an interactive collapsible hierarchy — click any node to expand or collapse it. Useful for exploring deeply nested structures.