773 Area Code: Chicago, Illinois

The 773 area code covers the city of Chicago outside the downtown core — the residential neighborhoods that stretch across the North, West, and South Sides of the city, from the lakefront communities through the mid-city neighborhoods and out to the city's edges. The 773 designation was carved out of the older 312 in the mid-1990s as Chicago's number demand pushed past what a single citywide code could support, and it has remained the primary code for the city's residential footprint since.

Records the directory has compiled for 773 numbers frequently include other Illinois cities — Aurora, Belleville, Cicero, and Peoria among them. None of those are inside the 773 footprint. The pattern reflects standard public-record dynamics, with phone numbers porting across Illinois and addresses linked across multiple cities. The directory currently documents 727 distinct prefixes within 773 in detail, a working subset of the prefix population the code carries.

Chicago's population dominates the demographic story: the city sits among the largest in the country, with several million residents within city limits and a metropolitan area many times that. Home values within the city run a touch above the US median, household income lands close to the national reading, and the city's median age skews a few years under the US figure. The 773 footprint specifically covers the residential city outside the Loop and downtown core, with neighborhood-level readings that vary widely across the city's many distinct communities.