Are files uploaded to a server?
No. Your input is handled locally in the browser. Some tools load JavaScript libraries from public CDNs, but NowConverter has no file-upload endpoint.
JSON formatter and validator
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About this tool
JSON formatter and validator without uploading
Paste a JSON object or open a JSON text file. Format it with two or four spaces, compact it to one line or validate whether its syntax is correct.
Before you start
Validation checks JSON syntax. It does not check an API-specific schema or verify that values are semantically correct.
Do I need an account or a paid plan?
No. The current version is free, has no registration and runs on devices with a compatible modern browser.
Can I check whether JSON is valid?
Yes. Paste your JSON or open a JSON text file and run validation. You can also format or minify valid JSON.
Valid JSON has stricter rules than JavaScript object notation
JSON requires double-quoted property names and strings, does not allow comments, and cannot contain trailing commas. Formatting changes whitespace only; minifying does not encrypt or otherwise protect the data. Validation is useful before sending configuration or API payloads because a single missing quote or bracket can prevent a parser from reading the whole document.
A syntactically valid file can still be semantically wrong for the system that receives it. An API may require particular keys, data types or value ranges. Use syntax validation as the first check, then compare the structure with the schema or documentation for the destination.
Practical checks
- Use formatting to make deeply nested structures easier to inspect.
- Do not treat minification as a privacy or security measure.
- Validate against the receiving system's expected schema when one exists.
Practical walkthrough · json tools
Validate configuration before committing it
Example task: A configuration includes {"enabled":true,"count":3} and must parse as JSON.
Try this workflow
- Paste the document and run the validator/formatter.
- Check that booleans are unquoted and property names use double quotes.
- Copy the formatted version into the actual application and test its expected behavior.
What to expect
Valid JSON syntax means a parser can read it; it does not establish that the application recognizes the keys or values.
When to take extra care
Trailing commas and comments are not part of strict JSON. Formatting does not validate an external schema or business rules.