Add the requested inputs
Use the labelled fields in the workspace above. If example values are provided, try them first or replace them with your own.
Developer tools · Free online tool
JSON formatter & validator
Validate, format, minify and recursively sort JSON entirely in your browser.
3 guest runs per rolling 24 hours10 with a free accountPrivate inputsMobile-friendly
JSON formatter & validator workspace
Runs locally in your browser
Large integers and duplicate keys can change when JSON is parsed. Review important data after formatting.
Result
Use it with confidence
How to use the JSON formatter & validator.
Calculate and review
Use the main action when needed. The input is parsed with the browser JSON parser and serialised with the selected indentation or compact output.
Try a worked example
Paste an API response, format it with two or four spaces, inspect errors, then copy the clean result.
Check the assumptions
Duplicate object keys are overwritten during parsing and very large integers can lose precision in JavaScript.
Helpful answers
JSON formatter & validator FAQs.
Is the JSON formatter & validator free?
Yes. Guests receive 3 runs per rolling 24 hours, verified free accounts receive 10, and Premium subscribers receive unlimited normal use.
Does UtilHub upload or save my inputs?
No. This tool runs in your browser and UtilHub does not receive or store the values you enter. Your browser or device may still retain normal local history or form data.
How does this JSON formatter & validator work?
The input is parsed with the browser JSON parser and serialised with the selected indentation or compact output.
What should I check before using the result?
Duplicate object keys are overwritten during parsing and very large integers can lose precision in JavaScript.