JSON Formatter and Validator Online
Format JSON into a consistent layout and check whether its syntax can be parsed correctly. JSONFlow combines readable output with error location details, tree inspection, JSON Schema validation and JSONPath queries in one workspace.
How to use this JSON tool
- Paste or upload the JSON document you want to check.
- Read the validation status and correct any reported line or column error.
- Press Format to apply consistent indentation to valid data.
- Use JSON Schema or JSONPath when you need structural validation or targeted extraction.
Formatting and syntax validation together
A JSON formatter should do more than insert line breaks. Before generating output, JSONFlow parses the document and reports whether it was accepted in strict, lenient or recovery mode. Strict success means the input can be treated as standard JSON; other modes help you inspect imperfect data while keeping the warning visible.
Common problems include trailing commas, missing quotation marks, mismatched brackets and unexpected characters. The error location gives you a practical starting point for repair. After correction, the same workspace can format the document with your preferred indentation or minify it for transport.
Validate structure and query the result
Valid syntax does not guarantee that an API payload has the fields or data types your application expects. The JSON Schema panel lets you test the parsed document against a schema and inspect validation messages. For exploration, enter a JSONPath expression to select nested values without manually expanding every branch.
All parsing and validation takes place in the browser. Nothing in the input editor is uploaded to a JSONFlow application server, and no account is required.
Frequently asked questions
What JSON errors can the formatter detect?
It detects parsing failures such as missing delimiters, mismatched braces or brackets, invalid quoting and unexpected tokens, and reports a useful location when available.
What is JSON Schema validation?
JSON Schema checks the shape of valid JSON, including required properties, allowed data types and other constraints defined by a schema.
Is the JSON formatter free?
Yes. JSONFlow can be used without registration or payment.