Naperville, IL is currently using an area code overlay in which area codes 331 and 630 serve the same geographic area. Ten digit dialing (area code + seven digit number) is necessary.
In addition to Naperville, IL area code information read more about area codes 331 and 630 details and Illinois area codes.
Naperville, IL is located in DuPage County and observes the Central Time Zone.
View our Times by Area Code tool.