What is this tool?
Validate JSON syntax compliance against RFC 8259 specifications. Pinpoints exact error line numbers, column positions, unescaped characters, unclosed brackets, and trailing commas with plain-language explanations.
When to use it?
Quickly find why a configuration file or API payload fails to parse, detect invisible invalid control characters, or verify JSON compliance before committing code to production.
How does it work?
Executes standard JavaScript JSON parsing routines within a protected try/catch boundary, captures lexical errors, parses browser-specific error offset messages (Firefox line/col and Chromium byte position), and cross-references the error token against the source text to provide contextual guidance.
Technical Specifications & Standards
JSON validator checks strict type validity for objects, arrays, numbers, strings, booleans (true/false), and null.
Operating Limits & Considerations
- This validator checks JSON structural and lexical syntax. It does not validate payloads against JSON Schema specifications ($schema).
Example Conversions
{
"service": "auth",
"enabled": true,
}Syntax Error at line 4, col 1: Trailing comma detected before closing brace "}".
Standards & Technical References
Frequently Asked Questions
Common causes include trailing commas after the last property, using single quotes instead of double quotes, missing closing braces/brackets, or unescaped control characters inside strings.
Yes. The validator calculates both the line number and character column index where the parsing error occurred.