JSON Formatter
Format and validate JSON locally in your browser.
Free. No signup required.
What this tool does
Format and beautify JSON in your browser. Choose indentation, inspect nested objects and check syntax while keeping API payloads on your device.
How to use
Paste JSON, choose indentation, then format. Expand objects in the result or copy the full JSON.
Features
Choose two spaces, four spaces or tabs and inspect nested objects in the result.
When to use it
Make a compact API response readable before investigating a missing field.
Example and checks
Formatting adds layout around objects and arrays; it does not repair invalid syntax. This two-space example makes the nested item visible. Keep identifiers beyond JavaScript's safe integer range quoted, and avoid duplicate keys: parsing can change those values before formatting. Use the tree to inspect structure, then compare the result with the original before copying it into a configuration.
{"items":[{"name":"demo","active":true}]}
{
"items": [
{
"name": "demo",
"active": true
}
]
}Common questions
Will large numeric identifiers stay exact?
JSON numbers use JavaScript precision. Quote large identifiers to preserve them exactly.
Data processing
This tool processes its input locally in your browser without sending it to a server for processing. Input and results are not included in share URLs.
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