What Are the Most Common JSON Errors and How to Fix Them?
Quick Error Fixes
Most JSON errors can be quickly identified and fixed. Here are the top solutions:
- 🔧Check for missing or extra commas
- 🔧Ensure all strings use double quotes
- 🔧Match all opening and closing brackets
- 🔧Remove trailing commas
1. Missing or Extra Commas
One of the most frequent JSON errors is incorrect comma usage. JSON requires commas between elements but not after the last element.
❌ Incorrect
{
"name": "John",
"age": 30,
"city": "New York",
}Trailing comma after "New York"
✅ Correct
{
"name": "John",
"age": 30,
"city": "New York"
}No trailing comma
2. Single Quotes Instead of Double Quotes
JSON strictly requires double quotes for strings and property names. Single quotes will cause syntax errors.
❌ Incorrect
{
'name': 'John',
'hobbies': ['reading', 'coding']
}Using single quotes
✅ Correct
{
"name": "John",
"hobbies": ["reading", "coding"]
}Using double quotes
3. Unmatched Brackets and Braces
Every opening bracket or brace must have a corresponding closing bracket or brace.
Common Bracket Errors:
- • Missing closing brace (opening brace without closing)
- • Missing closing bracket (opening bracket without closing)
- • Wrong bracket type (mixing square and curly brackets)
- • Extra brackets or braces
4. Invalid Data Types
JSON only supports specific data types. Using unsupported types will cause errors.
❌ Unsupported Types
- •
undefined - •
function() - •
new Date() - •
Infinity
✅ Valid Types
- •
null - •
"string" - •
42 - •
true/false
5. Debugging Tips
- 💡Use a JSON Validator
Always validate your JSON with a tool that shows specific error locations.
- 💡Check Line by Line
Start from the line number mentioned in the error message.
- 💡Use Proper Formatting
Well-formatted JSON makes it easier to spot structural errors.
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