ErrorJSON · .json
JSON Single Quotes — Invalid String Delimiters
A JSON file using single quotes instead of double quotes for strings. This is valid JavaScript syntax but violates the JSON specification.
Why It Fails
JSON requires all strings to be enclosed in double quotes ("). Single quotes are not part of the JSON grammar. This commonly occurs when developers copy JavaScript object literals into JSON files.
Broken Example
{
'name': 'Alice',
'city': 'New York'
}Expected Error Behavior
JSON.parse() throws SyntaxError: Unexpected token ' in JSON. Most APIs return 400 Bad Request when receiving single-quoted JSON.
Affected Software
JSON.parse()All strict JSON parsersREST APIsGraphQL endpoints
How to Fix
Replace all single quotes with double quotes. Use JSON.stringify() to generate valid JSON from JavaScript objects.