When this tool helps
- Locate a JSON syntax error
- Pretty-print an API response
- Minify JSON before embedding or transfer
DEVELOPER
JSON Formatter & Validator
Format, minify and validate JSON without uploading it.
Runs locallyNothing is uploaded
PRACTICAL GUIDE
How to use JSON Formatter
Last reviewed
Parse, validate, format or minify JSON locally. Formatting changes whitespace only; it does not intentionally alter keys, values or array order.
How to use it
- Paste JSON into the editor
- Choose format or minify
- Read any parser error before changing the source
- Copy the validated output
Formatting an object
- Input
- {"ready":true,"items":[1,2]}
- Result
- Indented JSON with the same object and array values
The parser validates the complete input before a formatted result is produced.
Limits and assumptions
- JSON cannot contain comments or trailing commas
- Very large documents are limited by browser memory
- Formatting does not validate an external API schema
Frequently asked questions
Does formatting change my JSON data?
It changes whitespace representation while preserving parsed keys, values and array order.
Why are comments rejected?
Comments are not part of the JSON standard.
Is JSON sent to a server?
No. Parsing and formatting run locally in the browser.