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779 Area Code

Area code 779 serves Joliet, Rockford, Plainfield, Crystal Lake, DeKalb and nearby communities in Illinois. It has been in service since March 17, 2007, when it was split from 815.

StateIllinois
Time zoneCentral
Local time now…
Prefixes in use354
Overlay with815
Projected to run out2044
JolietRockfordPlainfieldCrystal LakeDeKalbMcHenryNew LenoxLockportWoodstockBelvidereHomer GlenLoves ParkKankakeeFreeportMachesney ParkFrankfortSycamoreShorewoodBourbonnaisBradleyMorrisDixonChannahonSterlingMinookaStreatorRoscoeManhattanPontiacPeruHarvardRochelleLaSalleMantenoRock FallsSouth BeloitRocktonMarengoPrincetonSandwichMendotaLakemoorJohnsburgBraidwoodCoal CityWilmingtonWonder LakeGenoaSpring GroveCandlewick LakeSpring ValleyPoplar GroveJolietRockfordDeKalbMcHenry
Cities and towns served by area code 779

Who issues 779 numbers

Mobile 29%VoIP and cable 37%Landline 34%

Share of the 354 prefixes (the three digits after 779) assigned to each type of carrier. Classification by carrier name, approximate.

CarrierPrefixes
Onvoy (Sinch)57
AT&T Mobility43
Stratus Networks35
T-Mobile25
Fractel24
Verizon Wireless23
Bandwidth16
Ton80 Communications13

Cities and towns in area code 779

CityPopulationOther area codes
Joliet152,241815
Rockford147,384815
Plainfield50,043815
Crystal Lake42,288815
DeKalb40,467815
McHenry29,217815
New Lenox28,893815
Lockport27,822815
Woodstock25,740815
Belvidere25,462815
Homer Glen24,873815
Loves Park23,712815
Kankakee23,400815
Freeport23,202815
Machesney Park22,805815
Frankfort21,365815
Sycamore19,083815
Shorewood18,536815
Bourbonnais17,658815
Bradley15,214815
Morris14,669815
Dixon14,582815
Channahon14,530815
Sterling14,394815
Minooka12,899815
Streator12,190815
Roscoe11,034815
Manhattan10,943815
Pontiac10,806815
Peru9,780815
Harvard9,504815
Rochelle9,498815
LaSalle9,388815
Manteno9,201815
Rock Falls8,521815
South Beloit7,996815
Rockton7,870815
Marengo7,737815
Princeton7,674815
Sandwich7,380815

Showing the 40 largest of 52 places with 5,000+ residents.

Got a call from 779?

A 779 number was originally issued in Illinois, but that does not prove the caller is there. 37% of 779 prefixes belong to VoIP and cable providers, whose numbers can be bought online and used from anywhere. Caller ID can also be spoofed, so treat urgent requests for money, codes or passwords from any area code with suspicion, and call back on a number you already know.

All 354 prefixes in area code 779

Format: (779) XXX-YYYY. Carrier is the company the block was originally assigned to; numbers may since have been ported to another carrier.

Questions about area code 779

Where is area code 779?
Area code 779 is in Illinois. It covers Joliet, Rockford, Plainfield, Crystal Lake, DeKalb, McHenry and 46 more cities and towns.
What time zone is area code 779?
Area code 779 is in the Central time zone.
Is 779 a toll-free number?
No. 779 is a geographic area code in Illinois. Toll-free numbers in the US start with 800, 833, 844, 855, 866, 877 or 888.
Why does 779 share its area with 815?
779 and 815 form an overlay: they cover the same territory, so new numbers there can get any of these codes, and local calls need all 10 digits.
Will area code 779 run out of numbers?
NANPA's latest forecast projects the 779/815 overlay to exhaust in the first quarter of 2044. Before that happens, a new area code is usually added as an overlay; existing numbers keep their code.

Other area codes in Illinois