Which JSON layout provides better performance to fetch data?

I realized that using two different ways to organize JSON data may affect my code performance especially if I need to filter() or map(). The two cases are shown below, both cases will include thousands of lines of data:

[
   //....
   {
     "url": "www.example2400.com"
   }
   {
     "url": "www.example2401.com"
   }
   //...
]

Or:

{
   "url": [
    //...
    "www.example2400.com",
    "www.example2401.com",
    //...
    ]
}

Which layout would provide better performance in terms of fetch(), filter() or map() the data to render it on the page? Or is there a better layout?