[rzzzt]

JSON parsing treats non-quoted numerals as a Number. That alone can result in some truncation.

[taeric]

Though, in JSON, anything that isn't a number should be quoted?

[justsomehnguy]

If the JSON writer is writing according to spec

[beart]

I don't understand how this is at all a similar issue. If you want a string in JSON, then you must quote it.

https://www.json.org/json-en.html

[jodrellblank]

And if you want a string in Excel you must apostrophe-prefix it. If you think “serial number” == number, telephone number == number, then try to use the number handling, you get problems because “numbers” don’t have leading zeros or spaces or parens or hashes or plus symbols.

[rzzzt]

I would like to store, then retrieve exactly 1234567890123456789 apples instead of 1.070816993713379 × 2⁶⁰ = 1234567939550609408. Unfortunately due to IEEE-754 conversions I can only do this up to 7-8 digits or so. This is a number, just not one that can be represented as a Number without loss of precision towards the end.

[master-lincoln]

that's more apples than we can fit on the planet. For such special tasks I would think it's ok to need special tools