Loading...
Loading...
Validate, format, and beautify your JSON data with detailed error reporting and syntax highlighting.
Use JSON Validator to check whether a JSON document is syntactically valid before sending it to an API, config file, or test fixture. The tool reports parsing errors instead of silently changing your data. Valid JSON still needs schema review if the receiving system requires specific fields or nested types.
Wrap every JSON key in double quotes, for example use "name" instead of name.
Remove the comma after the final item in an object or array because strict JSON does not allow it.
Replace curly quotes copied from documents with standard double quotes.
Check the API schema after syntax validation because required fields and value types are separate rules.
JSON Validator parses the text in your browser, so request bodies and config snippets are not intentionally sent to a remote service. Remove tokens, passwords, and private customer values before validating examples on shared machines.
Use the exact request body, response sample, or config snippet that needs a syntax check.
Read the success message or parse error and note the approximate location of the syntax problem.
Fix missing quotes, commas, braces, brackets, or invalid characters in the input text yourself.
Repeat until the JSON parses, then check any separate schema or API requirements.
Paste your JSON data or upload a .json file for validation.
The validator checks syntax, structure, and formatting in real-time.
See detailed error messages with line numbers and suggestions for fixes.
Beautify your JSON with custom indentation and copy the formatted result.
Instant syntax checking as you type with live error highlighting.
Precise error messages with line numbers and column positions.
Beautify JSON with customizable indentation (2, 4, or 8 spaces).
Upload .json files for validation and formatting.
All validation happens in your browser — no data sent to servers.
Input: {"name":"Ada",}. Expected result: invalid JSON with an error near the trailing comma; remove the comma and validate again.
Input: {"user":{"id":1,"roles":["admin"]}}. Expected result: valid JSON syntax, while schema requirements still need separate review.
No. It reports whether the text is valid JSON and points you toward syntax problems. You edit the input yourself, then validate again.
The validator checks strict JSON syntax: double quoted property names, valid strings, balanced braces and brackets, commas between values, and no JavaScript comments.
Trailing commas are allowed in some JavaScript object literals but not in JSON. Remove the comma after the final property or array item and run validation again.
Yes. Paste the raw response body to confirm it is syntactically valid JSON before sharing it with a developer, adding it to docs, or using it as a fixture.
No. Valid JSON only means the syntax parses. A schema, API, or database may still reject the data because required fields, types, or business rules are wrong.
JSON (JavaScript Object Notation) is governed by two standards: RFC 8259 (IETF) and ECMA-404 (Ecma International). Valid JSON must follow strict rules — all strings must be double-quoted, no trailing commas are allowed, no comments are permitted, and specific escape sequences must be used. Common validation errors include trailing commas after the last array element (legal in JavaScript but not in JSON), single-quoted strings, and unescaped control characters. Our validator checks your JSON against the full specification and provides actionable error messages.
This tool is particularly useful when: