Why are returned JSON's big numbers rounded when pretty-printed?

Question

I am using ASP.NET core web application that fetches some data from database and returns a data transfer object serialized to JSON. I have noticed that when the data contains a big number (e.g. 70679185527693127) then the number is rounded when pretty-printed. I inspected the returned JSON using browser developer tools (Firefox & Chrome) and raw data is correct, but incorrect when pretty-printed. I have also tried to pretty-print the JSON using this website and the results are still the same. This is for some reason a problem for my Kendo grid that I am trying to show the data in as it shows the wrong rounded data. Why is that? Do I have to avoid using such big numbers?

Here is the very simplified JSON:

{"Data":[{"Id":70679185527693127}],"Total":1}

Here is the pretty-printed version:

{
  "Data": [
    {
      "Id": 70679185527693130
    }
  ],
  "Total": 1
}

See the difference in the values.

EDIT: Passing the value as a string works as expected (atleast using the mentioned website). Also a side question: why does the Kendo grid show the pretty-printed data instead of parsing the raw data which seem to be correct?

Answer 1

Pretty print is realized via JSON.parse() + JSON.stringify().

The value of your Id exceeds Number.MAX_SAFE_INTEGER so JSON.parse() will possibly parse an incorrect value.
I assume Kendo also uses JSON.parse() and thus will also display wrong values.

See also this question for more information