Developer & data
JSON formatter & validator
Validate JSON syntax, format it with indentation or minify it.
Runs in your browser · No file or text uploads
Preparing your tool…
What JSON formatter & validator helps you do
Make an API response or configuration file readable, or remove optional whitespace for a compact JSON representation.
How to use it
- Paste the JSON source.
- Choose formatted or minified output and indentation.
- Review validation messages and the resulting JSON.
Input and output example
INPUT
{"name":"Alex","active":true}OUTPUT{
"name": "Alex",
"active": true
}Supported formats and limits
- Maximum input: 1 MiB of UTF-8 JSON. Comments, trailing commas and JSON5 are unsupported.
- Numbers outside the safe integer range are rejected when they evaluate as integers. Other decimal values follow JavaScript floating-point precision.
How the result is calculated
Uses JSON.parse and JSON.stringify. JavaScript may place integer-like object keys first. Duplicate keys keep only their last value, so avoid duplicate keys. Formatting can normalize numeric notation and round decimal values.
Frequently asked questions
Is minification encryption?
No. It only removes optional whitespace; the content remains readable and reversible.
How should I enter long identifiers?
Use quoted strings for identifiers, account numbers and large integers to preserve leading zeros and precision.