JSON Formatter & Validator
Beautify, minify and validate JSON with the exact error line and column, a collapsible tree view and key sorting.
About JSON Formatter & Validator
This JSON formatter and validator beautifies messy JSON with the indent you choose, minifies it for production, and checks that it is valid. If there is a mistake, the error message gives the exact line and column, so trailing commas, missing quotes and unmatched brackets are quick to fix.
Switch to the tree view to explore large responses as a collapsible JSON viewer, sort keys alphabetically, and copy or download the result. You can paste JSON or drop a .json file on the box. It is free, needs no sign-up, and your data is processed in your browser and never sent to a server, which matters for API keys and customer data.
How to use JSON Formatter & Validator
- Paste or type JSON in the input box (or drop a .json file on it).
- Choose the indent and whether keys should be sorted.
- Read the validation message — errors show the line and column.
- Switch to Tree view to explore, then copy or download the result.
Frequently asked questions
Is my JSON sent to a server?
No. Parsing, formatting and validation all happen in your browser, so API responses and config files with secrets stay on your device.
Why does it say “Trailing comma”?
Standard JSON does not allow a comma after the last item in an object or array. JavaScript accepts it, but JSON.parse and most APIs reject it.
Can it handle single quotes or comments?
No — those are not valid JSON. The validator points to the exact spot so you can replace single quotes with double quotes and remove comments.
Does sorting keys change my data?
Only the order of keys inside objects changes. Values and array order stay exactly the same.
How do I format JSON online?
Paste your JSON and it is pretty-printed with consistent indentation. Choose 2 spaces, 4 spaces or tabs, then copy or download it.
How do I check if JSON is valid?
Paste it in; a valid message appears, or an error with the line and column of the first problem.
What does a valid JSON format look like?
Keys must be in double quotes, strings use double quotes, and there are no trailing commas or comments, for example {"name": "Asha", "age": 30}.
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