Private JSON tool
JSON Formatter
Format, minify, and validate JSON locally in your browser. Invalid input shows a readable parse error on the page.
About browser JSON formatting
This tool parses JSON text in the browser and writes it back with your selected indentation. It does not upload the input or output.
Use it to check whether JSON is valid, pretty-print compact JSON, or minify formatted JSON before storing it somewhere else.
Does this upload my files?
No. Everything on this page runs locally in your browser, so your files are never uploaded to a conversion server. Close the tab and nothing is left behind.
After any required processing engine has loaded, repeated conversions can keep working offline. You can verify the claim with the site's reproducible browser privacy audit.
FAQ
Is my JSON uploaded?
No. Formatting and validation happen in your browser. The text is not uploaded.
Does this page validate JSON?
Yes. The formatter parses the text first and shows an error if the input is invalid JSON.
Can it minify JSON?
Yes. Choose Minified before running the formatter.
Does it change key order?
No. JSON.stringify keeps the parsed object key order from the input.