String createBinaryUrl(ByteData input, { String type: "application/octet-stream" })

Source

static String createBinaryUrl(ByteData input,
    {String type: "application/octet-stream"}) {
  Uint8List data = ByteDataUtil.toUint8List(input);
  return "data:${type};base64,${Base64.encode(data)}";
}