JSON Formatter and Minifier — Validate JSON in Your Browser
Validate JSON, format it with two-space indentation, or compact it into one line directly in your browser.
Loading the tool… JavaScript is required for processing on your device. The instructions and examples below are available without JavaScript.
How to use it
Paste valid JSON and choose an indented or compact result.
Good to know
This validates JSON syntax, not a schema. Very large integers can lose precision in JavaScript.
Format valid JSON for a quick review
Paste JSON, choose Pretty print, and run the tool. The compact input {"name":"Ada","active":true} becomes:
{
"name": "Ada",
"active": true
}Choose Minify to remove that presentation whitespace again. This is handy when you need to inspect a payload, then copy a compact version into a configuration field or request body.
What the validation checks
The tool parses the input as JSON first. It reports an error for common mistakes such as a missing comma, trailing comma, unquoted property name, or an unclosed string. It does not validate a schema or tell you whether a value has the right meaning for an API. A syntactically valid object can still have the wrong field names, types, or required values.
Keep precision-sensitive data as strings
Formatting uses JavaScript’s JSON parser and serializer. Very large integers can lose precision when parsed, so keep identifiers such as long account numbers in quotes: {"accountId":"12345678901234567890"}. The result may also normalize number spelling and whitespace. Do not use this formatter to preserve an exact signed payload or a file where byte-for-byte identity matters. It accepts up to 100,000 characters and runs locally in your browser.