This would've been useful if you knew what kind of number it was... JSON isn’t ambiguous when it comes to this. Numbers are arbitrary precision decimal numbers

This would've been useful if you knew what kind of number it was... JSON isn’t ambiguous when it comes to this. Numbers are arbitrary precision decimal numbers[1]. I’m guessing your issue is with how Javascript interprets JSON numbers as 32 bit floats. But that is a (mis-)feature of JavaScript and switching your serialization format to XML would not help, because JavaScript represents all numbers as 32-bit floats. [1] https://www.json.org/json-en.html https://www.json.org/json-en.html