Find out whether a document is valid JSON and, if it is not, where it breaks: the line and column of the first error, with the common causes (trailing commas, single quotes, unquoted keys, comments) called out.
Line and column of the first syntax error
Names the usual culprits: trailing commas, single quotes, comments
Summarises the structure when the document is valid
Frequently asked questions
Why is a trailing comma an error?
JSON is stricter than JavaScript. A comma after the last item in an object or array is not allowed by the JSON specification, even though most JavaScript engines accept it in code.