DynamoDB JSON Converter

About this tool

DynamoDB exposes item data as typed AttributeValue JSON: strings are wrapped as {"S":"..."}, numbers as {"N":"30"}, booleans as {"BOOL":true}, lists as {"L":[...]}, maps as {"M":{...}}, and sets as SS, NS, or BS. That shape is exact and useful for AWS APIs, but it is noisy when you just want to read or edit the data. This converter moves between the AWS typed shape and ordinary JSON.

Use Plain JSON → DynamoDB JSON when you are preparing an item for an AWS CLI, SDK, or test fixture. Use DynamoDB JSON → Plain JSON when you copied an item from a stream event, export, CLI response, or debugging log and want a readable object. Auto-detect treats input that already looks like DynamoDB typed JSON as typed input and converts it back to plain JSON; otherwise it marshals the plain JSON into typed AttributeValues.

The conversion is deterministic and local. There is no AWS SDK call, network request, credential lookup, or table access — it only reshapes the JSON you paste.

Worked examples

Plain JSON input:

{"id":"user#1","age":30,"active":true}

DynamoDB JSON output:

{
  "id": { "S": "user#1" },
  "age": { "N": "30" },
  "active": { "BOOL": true }
}

DynamoDB JSON input:

{"roles":{"SS":["admin","user"]},"score":{"N":"9.5"}}

Plain JSON output:

{
  "roles": ["admin", "user"],
  "score": 9.5
}

Limits and edge cases

• DynamoDB N values are stored as strings. This converter parses them into JSON numbers; very large or high-precision decimals may be rounded by JSON number handling in downstream tools.
• Binary values (B and BS) stay as base64 strings; the tool does not decode or re-encode binary data.
• Set types (SS, NS, BS) become plain arrays when unmarshalling. Plain JSON arrays marshal as DynamoDB lists (L) because JSON has no set type.
• A top-level plain object marshals as a DynamoDB item map. A top-level scalar or array marshals as a single bare AttributeValue.

FAQ