JSON Formatter
Format, validate, and minify JSON in your browser.
Your JSON stays in your browser. Large numbers and original key order are preserved.
How to use JSON Formatter
- Paste your JSON into the input, or load the sample to try it.
- Choose Format to make it readable, Validate to check syntax, or Minify to remove extra whitespace.
- Fix any reported syntax error, then copy the output for your project.
What is JSON Formatter?
JSON stores data as objects, arrays, strings, numbers, booleans, and null. Formatting adds indentation so nested data is easier to inspect. Minifying removes unnecessary whitespace; validation checks whether the input follows JSON syntax. These actions run locally in your browser.
- Readable output with selectable indentation
- JSON syntax validation with clear error messages
- Minified output for compact payloads
- Sample data, copy, and clear controls
A practical example
{"name":"ADEMN","tools":["JSON Formatter","Word Counter"],"free":true}{
"name": "ADEMN",
"tools": [
"JSON Formatter",
"Word Counter"
],
"free": true
}Frequently asked questions
Is my JSON uploaded?
No. Formatting and validation run in your browser. The tool does not send the text you enter to a server.
Why is my JSON invalid?
Common causes include trailing commas, unquoted property names, single quotes, and comments. JSON requires double-quoted strings and does not allow comments or trailing commas.
Does this tool validate a JSON schema?
No. It checks JSON syntax. It does not check whether particular fields exist or whether your data matches a JSON Schema or an API contract.
Can I use this for large numeric IDs?
Yes. The formatter preserves the original number text instead of rewriting parsed numeric values. Other JavaScript tools may round large numbers when parsing them, so use quoted strings for identifiers when exact precision must survive across systems.