JSON Formatter & Validator
Format, minify, and validate JSON online in your browser without uploading your text to a server. Invalid JSON shows the exact line and column of the error.
What this tool does
NexKit JSON Formatter & Validator formats JSON text with readable indentation, minifies it to a single compact line, and validates it - all entirely in your browser, updating live as you type.
Invalid JSON is rejected with the exact line and column of the first syntax error, rather than a generic "invalid JSON" message.
How to format or validate JSON
Paste your JSON into the box. Choose Format for readable, indented output, or Minify for a compact single-line version. If the JSON is invalid, the error message shows exactly where the problem is.
Privacy and file handling
Your JSON is processed entirely in your browser. It is not uploaded to NexKit servers by this tool.
Frequently Asked Questions
Is my text uploaded?
No. Your JSON is formatted and validated locally in your browser. It is not uploaded to NexKit servers by this tool.
Does this tell me exactly where my JSON is invalid?
Yes. Invalid JSON shows the exact line and column of the first syntax error, not just a generic error message.
Does this support JSON5 or JSONC (comments, trailing commas)?
Not yet - this tool validates standard JSON only. Comments and trailing commas are treated as syntax errors.