JSONフォーマッター
Format, validate, and beautify JSON with syntax highlighting.
1 lines
Input
Output
Enter JSON to see formatted output
keysstringsnumbersbooleansnull
Your data stays yours
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Everything runs in your browser
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Files are never sent to a server
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JSON Formatter FAQ
Answers to the most common questions about using this tool.
What does a JSON formatter do?
A JSON formatter (also called a JSON beautifier) takes minified or messy JSON and reformats it with consistent indentation and line breaks so the structure is easy to read and debug. It also validates your JSON and highlights syntax errors with their exact location.
Is JSON Formatter free and safe to use?
Yes. ConvTop JSON Formatter is completely free with no sign-up required, and all formatting, validation and minification happen locally in your browser — your data never leaves your device.
How do I format JSON online?
Paste your JSON into the input panel (or click Sample), then press Format. The tree view lets you expand, collapse and search the structure. Use Minify to compress JSON into a single line, then Copy or Download the result.
Does it support invalid JSON error messages?
Yes. When you paste invalid JSON, the validator reports the exact error message and location, so you can find a missing comma or unclosed bracket in seconds.
Is this tool free to use?
Yes — every ConvTop tool is 100% free, with no sign-up, no limits and no watermark.
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