Free browser tool
JSON formatter & validator
Validate and format JSON locally, or make it compact for copying.
How to use this tool
JSON requires quoted property names, double-quoted strings and no trailing commas. This tool parses and serializes your input in the browser. Duplicate keys keep their last value; very large numbers can lose precision, so store long identifiers as quoted strings. Formatting does not check an application-specific schema. Maximum input: 1 MB.
Private by design
The calculation runs in your browser. There is no account requirement, input upload or subscription. Clear the fields when using a shared device.