Error: DynamoDB Error Message KeyError item is not JSON serializable

Answered by Rafal Wilinski
What's Causing This Error
This error indicates that the JSON module cannot transform the specific item in question into a JSON-formatted string. It can occur when making a typographical error in the list of JSON data you are serializing.
Solution: Here's How To Resolve It
First, check and verify whether there is no syntax error in the specific key and unnecessary punctuation marks are not used. If there is any, it will result in causing a KeyError
because the key is unidentified.
Other Common DynamoDB Errors (with Solutions)
- AWS CLI DynamoDB Error Parsing Parameter
- dynamodb throttle error code
- DynamoDB Is Not Null
- dynamodb cannot convert undefined or null to object
- resourcenotfoundexception dynamodb nodejs
- dynamodb atomic counter not working
- 'dynamodb' object has no attribute 'table'
- DynamoDB Mapper Could Not Instantiate Class
- appsync dynamodb not seeing all fields
- dynamodb does not support null values
- dynamodb converter not found for enhancedtype
- DynamoDB Update Not Working
- dynamodb cannot read property '0' of undefined
- DynamoDB Not Supported Requires @DynamoDBTyped Or @DynamoDBTypeConverted
- AWS DynamoDB errors ResourceNotFoundException
Better DynamoDB experience.
Try 7-day free trial. No strings attached.
Product Features
DynamoDB Tools
DynamoDB Info
© 2025 Dynobase