Single item size limit of 400KB

5/10 Medium

DynamoDB enforces a hard 400KB limit per item, significantly smaller than competing document databases (MongoDB 16MB, Cassandra 2GB). Applications storing large objects must split data across items or use external storage like S3, adding architectural complexity.

Category
architecture
Workaround
hack
Freshness
persistent
Scope
single_lib
Upstream
wontfix
Recurring
No
Buyer Type
team
Maintainer
active

Sources

Collection History

Query: “What are the most common pain points with DynamoDB for developers in 2025?4/5/2026

The size limit for an item is 400KB, and it is essential to note that the users cannot increase this value in any way. This limitation can be restrictive for applications that need to store large objects or documents within a single item.

Created: 4/5/2026Updated: 4/5/2026