ILLINOIS · AREA CODE GUIDE
779 and 815 area codes location: Joliet and Rockford, Illinois
- Local date and time
- Central Time
Map data: UCLA Geoportal (2015) · NANPA · US Census Bureau, checked 26 September 2026. Boundaries are approximate.
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Download the 779 area code map
779 and 815 area codes at a glance
- State
- Illinois
- Primary cities
- Joliet, Rockford, and Plainfield
- Time zone
- Central Time
- Answering calls
- Rules for answering calls in Illinois
An area code does not show where a caller is now.
| Area code | Started service | Parent code | New code planned |
|---|---|---|---|
| 779 | 815 | No, as of 22 September 2026 | |
| 815 | No, as of 22 September 2026 |
History
- : 779 added as an overlay on 815
Counties and cities covered
These are telephone exchange areas, which follow the phone network rather than city limits.
Counties of the communities we could place (the code may reach further): Boone County, Bureau County, Carroll County, Cook County, DeKalb County, Ford County, Grundy County, Henry County, Iroquois County, Jo Daviess County, Kane County, Kankakee County, Kendall County, LaSalle County, Lee County, Livingston County, Marshall County, McHenry County, McLean County, Ogle County, Putnam County, Stephenson County, Whiteside County, Will County, and Winnebago County.
- Joliet
- Rockford
- Plainfield
- Crystal Lake
- Dekalb
- McHenry
- New Lenox
- Lockport
- Woodstock
- Belvidere
- Kankakee
- Freeport
- Frankfort
- Sycamore
- Ottawa
- Morris
- Dixon
- Sterling
- Minooka
- Streator
- Roscoe
- Manhattan
- Pontiac
- Harvard
- Rochelle
173 more communities
- Manteno
- South Beloit
- Rockton
- Marengo
- Princeton
- Sandwich
- Mendota
- Braidwood
- Coal City
- Wonder Lake
- Genoa
- Spring Grove
- Spring Valley
- Poplar Grove
- Marseilles
- Watseka
- Dwight
- Morrison
- Byron
- Oglesby
- Fairbury
- Oregon
- Fulton
- Galena
- Momence
- Winnebago
- Cherry Valley
- Mount Morris
- Savanna
- Lena
- Seneca
- Elwood
- Polo
- Amboy
- Richmond
- Sheridan
- Pecatonica
- Hinckley
- Utica
- Prophetstown
- Somonauk
- Chenoa
- Gilman
- Stockton
- Waterman
- Kirkland
- Thomson
- Earlville
- Maple Park
- Herscher
- East Dubuque
- Lanark
- Mount Carroll
- Capron
- Forreston
- Hebron
- Ladd
- Durand
- Gardner
- Granville
- Toluca
- Onarga
- Clifton
- Warren
- Grant Park
- Walnut
- Chatsworth
- Malta
- Saint Anne
- Milford
- Stillman Valley
- Flanagan
- Forrest
- Chebanse
- Milledgeville
- Mazon
- Newark
- Odell
- Shirland
- Wenona
- Sheldon
- Ashton
- Leland
- Franklin Grove
- Shabbona
- Wyanet
- Shannon
- Hanover
- New Milford
- Paw Paw
- Sheffield
- Cissna Park
- Pearl City
- Hennepin
- Orangeville
- Tonica
- Piper City
- Ashkum
- Tiskilwa
- Elizabeth
- Union
- La Moille
- Tampico
- Cedarville
- Creston
- Davis
- Danforth
- Crescent City
- Lyndon
- Grand Ridge
- Cullom
- Dakota
- Chadwick
- Ohio
- Cornell
- Lostant
- Scales Mound
- German Valley
- Leaf River
- Monroe Center
- Saunemin
- Sublette
- Apple River
- Martinton
- Ransom
- Beaverville
- Manlius
- Winslow
- McNabb
- Lisbon
- Compton
- Cedar Point
- Magnolia
- Rutland
- Bureau
- Donovan
- Woodland
- Cabery
- Steward
- Plattville
- Verona
- Long Point
- Wellington
- Stockland
- Reddick
- Kempton
- Hooppole
- Coleta
- Campus
- Dover
- West Brooklyn
- Nelson
- Leonore
- Harmon
- Strawn
- Emington
- Kinsman
- Depue
- Garden Prairie
- Grand Detour
- Graymont
- Harding
- La Salle
- Massbach
- McConnell
- Putnam
- Rock Cut
- Seward
- South Bergen
- South Sharon
- Stelle
- Thomas
- Wilmington
Sources: NANPA area code listing, NANPA places by area code, U.S. Census Bureau county geography. Checked .
Business phone numbers in area codes 779 and 815, answered by an AI agent
A local number for Joliet, Rockford, and Plainfield, Illinois, with an AI receptionist that takes caller details, answers the questions you give it, and books appointments. Numbers depend on what carriers have left.