JSON Validator
Validate JSON syntax
Frequently Asked Questions
How does the JSON Validator check my JSON?
The validator parses your JSON against the RFC 8259 specification. It checks for proper syntax: matching brackets, correct comma placement, double-quoted strings, valid escape sequences, and proper value types (string, number, boolean, null, object, array).
What are the most common JSON errors?
Trailing commas after the last item, single quotes instead of double quotes, unquoted property names, comments (not allowed in JSON), missing commas between items, and unclosed brackets or braces. The validator pinpoints the exact error location.
Can I validate JSON against a schema?
Yes. Paste a JSON Schema (draft-07 or later) and the validator checks your JSON data against it. It verifies required fields, data types, value ranges, string patterns, and array constraints defined in the schema.
What is the difference between JSON and JSONC?
Standard JSON does not allow comments or trailing commas. JSONC (JSON with Comments) permits // and /* */ comments and trailing commas. The validator can operate in strict JSON mode or relaxed JSONC mode.
Does the validator handle large JSON files?
The validator processes files up to 5MB efficiently in the browser. For very large files, it streams the parsing to avoid memory issues. Error reporting includes line and column numbers for quick navigation to problems.