Is DynamoDB open source?

No. DynamoDB is a proprietary, fully managed AWS service — the source code is not public and you cannot self-host the production engine. For local development, AWS ships DynamoDB Local, a free downloadable emulator, and some third-party databases advertise DynamoDB-compatible APIs you can run yourself.

What that means in practice

DynamoDB only runs inside AWS. You consume it as an API — there is no server software to download, license, inspect, or operate, and no community edition. That is also its selling point: AWS handles setup, patching, replication, scaling, and backups, and the service has no versions or maintenance windows.

DynamoDB Local is free, not open

AWS provides DynamoDB Local, a downloadable version of DynamoDB that runs on your computer as a Docker image, Java archive, or Apache Maven dependency. It is free to use and works offline, but it is an emulator for development and testing — not the production engine, and not open source either.

The emulator is not the engine

The gap matters more than the license does, because the emulator never enforces capacity. Create a table at 1 RCU, store an item just under 4 KB, then read it back strongly consistent in a sequential loop:

for (let i = 0; i < 500; i++) {
  await client.send(
    new GetItemCommand({TableName: 'demo', Key: {pk: {S: 'HOT'}}, ConsistentRead: true})
  );
}

500 reads finished in 353 ms and nothing throttled. That is roughly 1,400 strongly consistent reads a second against a table provisioned for one. The emulator accepts ProvisionedThroughput and then ignores it.

Against the real service the same shape of loop throttles on the 49th read, once the accumulated burst credit runs out.

So a load test that stays green locally tells you nothing about capacity. Neither does a local test of retry and backoff, because nothing ever gets throttled to retry.

Compatible alternatives

Because the DynamoDB API is well documented, some open-source and third-party databases implement DynamoDB-compatible endpoints. Compatibility varies by feature, so verify the operations you rely on (transactions, streams, secondary indexes) before treating any of them as a drop-in replacement.

Go deeper

Run the emulator locally with the DynamoDB Local guide, build queries visually in the expression builder, and download DynoTable — it connects to both AWS and local endpoints.

References

Last verified 2026-07-13 against the official AWS documentation linked above.

Measured 2026-07-28 against DynamoDB Local 3.3.0 via @aws-sdk/client-dynamodb 3.1095.0 on Node v24.18.0. The 49-read live-service figure comes from our own earlier reproduction against DynamoDB in us-east-1.