AT&T currently ranks first for coverage in this area, with a coverage score of 79.3. Compare Wireless Carriers uses FCC broadband map data to estimate and calculate coverage scores. More on that further below.Coverage rankings for Illinois
| Rank | Carrier | Score | Overall | 4G LTE | 5G | Fast 5G | Average Signal |
|---|---|---|---|---|---|---|---|
| 1 | AT&T | 79.3 | 95.7% | 95.6% | 71.5% | 53.8% | -111 dBm |
| 2 | T-Mobile | 75.8 | 78.5% | 78.5% | 68.5% | 50.7% | -91 dBm |
| 3 | Verizon | 75.1 | 97.5% | 97.5% | 46.4% | 33.0% | -93 dBm |
Scores include coverage area, network type, and average signal strength.
Cell phone coverage map for Illinois
Zoom in for local detail. Tap or click a colored area to see coverage and signal details. On mobile, use two fingers to move the map.
Coverage Key
Less covered More covered
Darker areas mean the carrier covers more of that location.
Map data © OpenStreetMap contributors, © CARTO. Rendered with MapLibre. FCC BDC mobile coverage processed by Compare Wireless Carriers.
Loading coverage map...
Cell phone coverage by network in Illinois
#1
AT&T
Coverage Score 79.3
In Illinois
- Overall
- 95.7%
- 4G LTE
- 95.6%
- 5G
- 71.5%
- Fast 5G
- 53.8%
Average Signal -111 dBm
#2
T-Mobile
Coverage Score 75.8
In Illinois
- Overall
- 78.5%
- 4G LTE
- 78.5%
- 5G
- 68.5%
- Fast 5G
- 50.7%
Average Signal -91 dBm
#3
Verizon
Coverage Score 75.1
In Illinois
- Overall
- 97.5%
- 4G LTE
- 97.5%
- 5G
- 46.4%
- Fast 5G
- 33.0%
Average Signal -93 dBm
Sponsored US Mobile
Coverage varies by neighborhood. Your carrier shouldn’t.
US Mobile lets you switch between all three major networks, so you can choose the one that works best where you actually use your phone.
Choose your network
Dark Star Light Speed Warp 5G
Unlimited plans from
$22.50/mo
Phone + home internet bundle from
$47/mo
Shop US Mobile
Pricing, network access, switching terms, and home internet availability may vary.
Coverage by county in Illinois
Counties are shown for statewide comparison. Coverage percentages use land-area only coverage.
| County | Verizon | AT&T | T-Mobile |
|---|---|---|---|
| Adams County, IL | 97.8% 97.8% 8.2% 2.7% -95 dBm | 90.2% 90.2% 68.8% 49.6% -113 dBm | 63.8% 63.4% 51.3% 34.9% -94 dBm |
| Alexander County, IL | 88.2% 88.2% 5.8% 2.6% -97 dBm | 89.4% 89.2% 69.7% 47.0% -114 dBm | 31.3% 31.3% 24.1% 17.5% -93 dBm |
| Bond County, IL | 97.8% 97.8% 61.2% 41.9% -95 dBm | 97.4% 97.4% 79.6% 67.3% -112 dBm | 81.7% 81.7% 72.2% 52.5% -93 dBm |
| Boone County, IL | 100.0% 100.0% 65.1% 37.2% -94 dBm | 99.7% 99.7% 81.5% 46.7% -113 dBm | 99.4% 99.4% 96.9% 84.3% -87 dBm |
| Brown County, IL | 93.9% 93.9% 0.0% 0.0% -96 dBm | 77.5% 77.4% 52.3% 31.8% -113 dBm | 35.9% 35.9% 27.1% 16.5% -96 dBm |
| Bureau County, IL | 100.0% 100.0% 38.3% 18.6% -95 dBm | 98.6% 98.6% 55.4% 48.6% -114 dBm | 81.7% 81.7% 69.4% 46.0% -94 dBm |
| Calhoun County, IL | 96.1% 96.1% 18.8% 12.4% -98 dBm | 81.4% 80.7% 52.8% 36.6% -116 dBm | 32.3% 32.3% 17.8% 6.1% -100 dBm |
| Carroll County, IL | 99.8% 99.8% 29.4% 14.6% -96 dBm | 84.4% 84.4% 3.3% 2.7% -110 dBm | 39.0% 38.9% 22.2% 10.4% -100 dBm |
| Cass County, IL | 87.5% 87.5% 0.0% 0.0% -98 dBm | 94.6% 94.6% 78.4% 52.2% -110 dBm | 79.7% 79.7% 66.6% 49.7% -94 dBm |
| Champaign County, IL | 99.8% 99.8% 93.8% 71.0% -91 dBm | 99.9% 99.8% 96.4% 67.7% -107 dBm | 98.5% 98.5% 94.4% 75.5% -90 dBm |
| Christian County, IL | 98.9% 98.9% 56.6% 36.1% -92 dBm | 99.1% 99.0% 93.7% 73.6% -110 dBm | 89.5% 89.5% 77.1% 50.0% -94 dBm |
| Clark County, IL | 95.0% 94.9% 38.5% 28.6% -95 dBm | 83.8% 83.7% 55.8% 35.6% -115 dBm | 44.7% 44.7% 35.1% 21.2% -96 dBm |
| Clay County, IL | 99.1% 99.1% 42.0% 35.4% -89 dBm | 95.2% 95.2% 51.6% 44.2% -113 dBm | 75.0% 75.0% 61.7% 40.9% -95 dBm |
| Clinton County, IL | 97.2% 97.2% 73.0% 55.0% -93 dBm | 99.0% 99.0% 89.2% 66.7% -109 dBm | 87.7% 87.7% 80.3% 62.5% -91 dBm |
| Coles County, IL | 97.6% 97.6% 65.5% 58.5% -90 dBm | 97.7% 97.7% 81.9% 66.1% -111 dBm | 87.0% 87.0% 79.1% 67.6% -88 dBm |
| Cook County, IL | 100.0% 100.0% 99.1% 92.0% -87 dBm | 99.9% 99.9% 99.2% 78.3% -97 dBm | 99.9% 99.9% 99.2% 96.6% -77 dBm |
| Crawford County, IL | 96.2% 96.1% 48.9% 35.5% -96 dBm | 85.0% 85.0% 30.1% 18.1% -113 dBm | 27.6% 27.6% 21.8% 11.9% -96 dBm |
| Cumberland County, IL | 99.5% 99.5% 58.1% 43.1% -92 dBm | 99.4% 99.4% 75.9% 66.8% -111 dBm | 69.3% 69.3% 56.6% 39.1% -94 dBm |
| De Witt County, IL | 99.3% 99.3% 67.6% 53.3% -91 dBm | 99.7% 99.7% 94.0% 64.5% -110 dBm | 94.8% 94.7% 92.6% 74.4% -90 dBm |
| DeKalb County, IL | 100.0% 100.0% 70.2% 45.6% -91 dBm | 99.5% 99.5% 85.3% 57.7% -113 dBm | 99.5% 99.5% 98.5% 93.2% -84 dBm |
| Douglas County, IL | 99.7% 99.7% 80.5% 63.1% -90 dBm | 99.8% 99.8% 88.4% 76.2% -108 dBm | 94.4% 94.4% 88.4% 65.7% -92 dBm |
| DuPage County, IL | 100.0% 100.0% 99.8% 96.4% -86 dBm | 100.0% 99.9% 99.5% 70.4% -99 dBm | 100.0% 100.0% 99.8% 98.6% -79 dBm |
| Edgar County, IL | 97.0% 97.0% 71.6% 50.4% -94 dBm | 94.2% 94.1% 58.0% 44.3% -115 dBm | 57.2% 57.2% 41.3% 19.3% -100 dBm |
| Edwards County, IL | 99.9% 99.9% 4.1% 2.3% -94 dBm | 99.7% 99.7% 69.6% 59.3% -113 dBm | 50.2% 50.2% 35.2% 19.2% -98 dBm |
| Effingham County, IL | 98.8% 98.8% 48.0% 33.8% -92 dBm | 94.1% 94.1% 67.4% 50.7% -113 dBm | 80.5% 80.5% 68.6% 49.8% -93 dBm |
| Fayette County, IL | 92.1% 91.9% 49.7% 30.9% -97 dBm | 93.2% 93.2% 64.1% 55.2% -114 dBm | 65.2% 65.2% 52.5% 33.3% -95 dBm |
| Ford County, IL | 99.9% 99.9% 35.7% 19.7% -90 dBm | 100.0% 100.0% 95.3% 77.0% -114 dBm | 86.6% 86.6% 69.1% 41.3% -96 dBm |
| Franklin County, IL | 99.8% 99.8% 40.4% 25.8% -92 dBm | 99.5% 99.5% 90.7% 65.6% -109 dBm | 61.2% 61.2% 48.3% 29.4% -96 dBm |
| Fulton County, IL | 91.5% 91.4% 24.0% 17.4% -94 dBm | 96.3% 96.3% 49.3% 26.1% -112 dBm | 79.7% 79.7% 66.1% 45.6% -94 dBm |
| Gallatin County, IL | 86.5% 86.5% 18.0% 7.9% -97 dBm | 87.4% 87.4% 31.4% 24.1% -114 dBm | 55.2% 55.2% 46.0% 29.9% -95 dBm |
| Greene County, IL | 97.2% 97.2% 4.1% 2.2% -96 dBm | 96.5% 96.4% 79.2% 61.0% -113 dBm | 63.9% 63.9% 50.6% 33.1% -95 dBm |
| Grundy County, IL | 100.0% 100.0% 82.7% 58.9% -93 dBm | 99.6% 99.6% 92.7% 80.1% -113 dBm | 94.5% 94.5% 88.5% 69.9% -89 dBm |
| Hamilton County, IL | 99.3% 99.3% 12.5% 5.2% -95 dBm | 98.9% 98.9% 71.0% 63.5% -114 dBm | 59.2% 58.6% 48.0% 26.3% -97 dBm |
| Hancock County, IL | 94.7% 94.7% 30.2% 15.6% -96 dBm | 82.4% 82.4% 11.8% 9.4% -115 dBm | 66.9% 66.9% 47.8% 25.9% -98 dBm |
| Hardin County, IL | 79.0% 79.0% 0.0% 0.0% -102 dBm | 71.0% 70.9% 21.6% 19.5% -116 dBm | 35.5% 35.5% 24.6% 14.2% -98 dBm |
| Henderson County, IL | 94.7% 94.7% 4.3% 0.1% -99 dBm | 84.2% 84.2% 25.7% 23.0% -114 dBm | 73.1% 73.1% 49.3% 26.9% -98 dBm |
| Henry County, IL | 100.0% 100.0% 44.9% 24.0% -95 dBm | 99.3% 99.3% 58.4% 40.8% -112 dBm | 95.4% 95.4% 83.9% 59.1% -92 dBm |
| Iroquois County, IL | 99.9% 99.9% 55.2% 28.2% -93 dBm | 99.2% 99.2% 89.7% 83.9% -111 dBm | 82.3% 82.3% 62.5% 37.3% -96 dBm |
| Jackson County, IL | 93.8% 93.8% 20.2% 11.8% -95 dBm | 89.4% 89.3% 54.8% 39.0% -113 dBm | 62.4% 62.4% 53.1% 37.2% -93 dBm |
| Jasper County, IL | 97.0% 97.0% 16.8% 7.8% -94 dBm | 94.8% 94.7% 66.3% 58.5% -114 dBm | 46.8% 46.8% 36.6% 18.4% -98 dBm |
| Jefferson County, IL | 98.9% 98.9% 22.7% 14.2% -94 dBm | 99.2% 99.2% 82.0% 63.4% -111 dBm | 66.5% 66.5% 52.4% 34.0% -94 dBm |
| Jersey County, IL | 96.1% 96.1% 12.2% 3.2% -98 dBm | 91.8% 91.7% 55.5% 43.4% -114 dBm | 61.5% 61.5% 50.9% 34.9% -94 dBm |
| Jo Daviess County, IL | 99.5% 99.5% 21.2% 11.2% -97 dBm | 74.8% 68.2% 24.5% 17.3% -112 dBm | 68.3% 68.3% 53.1% 34.3% -94 dBm |
| Johnson County, IL | 96.8% 96.8% 12.3% 6.8% -98 dBm | 87.2% 87.1% 53.4% 37.2% -115 dBm | 50.7% 50.7% 39.8% 25.0% -95 dBm |
| Kane County, IL | 100.0% 100.0% 98.7% 86.6% -88 dBm | 100.0% 100.0% 97.7% 78.9% -106 dBm | 100.0% 100.0% 99.7% 97.2% -80 dBm |
| Kankakee County, IL | 100.0% 100.0% 88.7% 60.5% -92 dBm | 98.8% 98.8% 91.8% 83.4% -111 dBm | 96.0% 96.0% 88.3% 72.9% -89 dBm |
| Kendall County, IL | 100.0% 100.0% 99.3% 93.3% -88 dBm | 99.9% 99.9% 90.9% 62.7% -110 dBm | 99.9% 99.9% 99.7% 96.9% -80 dBm |
| Knox County, IL | 95.3% 95.2% 36.1% 27.9% -92 dBm | 96.8% 96.8% 63.2% 43.8% -112 dBm | 77.5% 77.5% 66.8% 48.1% -92 dBm |
| Lake County, IL | 100.0% 100.0% 98.8% 87.6% -89 dBm | 99.9% 99.9% 98.7% 71.2% -104 dBm | 99.9% 99.9% 99.4% 96.5% -80 dBm |
| LaSalle County, IL | 99.9% 99.9% 74.9% 47.4% -92 dBm | 99.5% 99.5% 91.8% 64.6% -112 dBm | 94.1% 94.1% 88.8% 72.8% -90 dBm |
| Lawrence County, IL | 99.9% 99.8% 64.1% 47.8% -92 dBm | 97.0% 97.0% 62.1% 59.2% -115 dBm | 45.8% 45.8% 38.1% 21.7% -96 dBm |
| Lee County, IL | 100.0% 100.0% 55.1% 29.8% -94 dBm | 97.0% 96.9% 42.7% 30.2% -112 dBm | 86.7% 86.6% 79.0% 56.7% -92 dBm |
| Livingston County, IL | 99.9% 99.9% 66.6% 45.3% -90 dBm | 99.7% 99.7% 93.0% 78.7% -111 dBm | 89.1% 89.1% 76.9% 53.0% -94 dBm |
| Logan County, IL | 99.2% 99.2% 59.7% 43.3% -91 dBm | 98.9% 98.9% 90.7% 59.1% -112 dBm | 94.4% 94.4% 88.0% 66.7% -91 dBm |
| Macon County, IL | 99.7% 99.7% 66.1% 53.6% -89 dBm | 99.8% 99.8% 93.7% 66.1% -110 dBm | 99.6% 99.5% 98.1% 86.7% -86 dBm |
| Macoupin County, IL | 94.7% 94.6% 27.5% 19.1% -96 dBm | 96.8% 96.8% 67.3% 40.7% -111 dBm | 63.6% 63.6% 51.5% 32.4% -96 dBm |
| Madison County, IL | 98.9% 98.8% 56.1% 39.2% -95 dBm | 99.6% 99.5% 93.2% 63.6% -108 dBm | 93.5% 93.5% 88.0% 73.9% -88 dBm |
| Marion County, IL | 94.0% 93.9% 61.0% 50.2% -94 dBm | 96.1% 96.1% 69.8% 55.9% -112 dBm | 77.5% 77.5% 65.9% 47.1% -94 dBm |
| Marshall County, IL | 99.6% 99.6% 53.1% 24.4% -96 dBm | 97.9% 97.9% 76.2% 62.4% -112 dBm | 72.4% 72.4% 47.0% 25.3% -98 dBm |
| Mason County, IL | 95.4% 95.3% 42.9% 29.3% -94 dBm | 98.5% 98.5% 80.8% 67.8% -112 dBm | 77.8% 77.8% 63.5% 40.9% -95 dBm |
| Massac County, IL | 98.5% 98.5% 17.7% 7.7% -96 dBm | 94.3% 94.2% 67.9% 50.6% -113 dBm | 79.3% 79.3% 66.9% 45.9% -93 dBm |
| McDonough County, IL | 94.2% 94.2% 1.6% 1.4% -90 dBm | 95.0% 95.0% 59.7% 29.1% -113 dBm | 91.0% 91.0% 79.6% 58.1% -92 dBm |
| McHenry County, IL | 100.0% 100.0% 97.7% 83.5% -91 dBm | 99.8% 99.7% 93.6% 77.3% -109 dBm | 99.6% 99.6% 98.4% 89.9% -84 dBm |
| McLean County, IL | 99.9% 99.9% 64.7% 54.7% -89 dBm | 100.0% 100.0% 96.3% 68.4% -108 dBm | 97.8% 97.8% 93.5% 80.3% -88 dBm |
| Menard County, IL | 96.2% 96.1% 34.5% 20.8% -96 dBm | 98.8% 98.8% 89.7% 74.0% -110 dBm | 82.9% 82.9% 69.7% 44.9% -95 dBm |
| Mercer County, IL | 98.7% 98.7% 16.1% 7.6% -97 dBm | 84.9% 84.9% 7.3% 4.4% -112 dBm | 83.7% 83.7% 70.3% 43.5% -94 dBm |
| Monroe County, IL | 94.8% 94.8% 58.4% 44.1% -99 dBm | 97.5% 97.1% 77.3% 39.6% -113 dBm | 81.4% 81.4% 72.6% 52.2% -93 dBm |
| Montgomery County, IL | 94.7% 94.7% 42.9% 25.5% -95 dBm | 96.8% 96.7% 80.0% 67.0% -112 dBm | 90.9% 90.9% 78.5% 55.6% -93 dBm |
| Morgan County, IL | 96.8% 96.8% 22.0% 11.6% -95 dBm | 98.9% 98.9% 84.7% 54.0% -107 dBm | 90.0% 90.0% 80.1% 61.3% -91 dBm |
| Moultrie County, IL | 100.0% 100.0% 27.5% 23.2% -86 dBm | 99.8% 99.8% 85.6% 74.8% -113 dBm | 95.6% 95.6% 88.8% 59.9% -93 dBm |
| Ogle County, IL | 100.0% 100.0% 46.0% 28.4% -92 dBm | 92.9% 92.9% 31.5% 20.9% -112 dBm | 87.7% 87.7% 77.7% 58.4% -91 dBm |
| Peoria County, IL | 96.8% 96.7% 51.2% 34.2% -93 dBm | 98.4% 98.4% 70.7% 49.5% -110 dBm | 91.6% 91.6% 83.0% 66.3% -89 dBm |
| Perry County, IL | 99.9% 99.9% 16.0% 8.4% -93 dBm | 99.4% 99.4% 82.1% 70.2% -112 dBm | 65.4% 65.4% 49.7% 28.2% -97 dBm |
| Piatt County, IL | 99.7% 99.7% 66.4% 50.3% -89 dBm | 99.8% 99.8% 98.5% 75.7% -109 dBm | 97.0% 97.0% 89.8% 65.0% -92 dBm |
| Pike County, IL | 98.7% 98.7% 2.0% 1.3% -94 dBm | 91.3% 91.1% 70.1% 52.0% -114 dBm | 63.3% 63.3% 47.7% 29.1% -95 dBm |
| Pope County, IL | 73.4% 73.4% 0.1% 0.0% -103 dBm | 56.1% 56.1% 23.5% 19.3% -118 dBm | 23.1% 23.1% 15.0% 7.9% -99 dBm |
| Pulaski County, IL | 99.6% 99.6% 15.4% 10.2% -96 dBm | 99.9% 99.9% 83.2% 66.5% -112 dBm | 58.7% 58.7% 45.9% 28.4% -95 dBm |
| Putnam County, IL | 99.9% 99.9% 25.2% 9.0% -97 dBm | 94.7% 94.6% 64.8% 42.9% -113 dBm | 61.6% 61.6% 48.3% 25.9% -97 dBm |
| Randolph County, IL | 97.4% 97.4% 20.7% 10.5% -97 dBm | 97.1% 97.1% 79.2% 59.6% -114 dBm | 74.6% 74.3% 62.5% 41.2% -95 dBm |
| Richland County, IL | 99.3% 99.3% 53.3% 44.2% -89 dBm | 99.0% 99.0% 74.6% 68.5% -112 dBm | 54.7% 54.7% 45.5% 26.2% -97 dBm |
| Rock Island, IL County | 99.9% 99.9% 48.4% 29.4% -95 dBm | 87.3% 87.2% 41.1% 28.8% -110 dBm | 90.0% 90.0% 79.0% 57.7% -91 dBm |
| Saline County, IL | 96.1% 96.1% 21.4% 11.9% -95 dBm | 96.0% 96.0% 73.3% 60.3% -113 dBm | 66.7% 66.7% 56.9% 39.9% -94 dBm |
| Sangamon County, IL | 99.1% 99.0% 68.2% 52.1% -91 dBm | 98.9% 98.7% 93.6% 61.4% -107 dBm | 95.7% 95.7% 90.6% 76.8% -88 dBm |
| Schuyler County, IL | 73.7% 73.7% 0.1% 0.0% -97 dBm | 82.3% 82.3% 24.4% 20.0% -114 dBm | 39.2% 39.2% 24.3% 15.8% -97 dBm |
| Scott County, IL | 98.4% 98.4% 18.0% 9.3% -96 dBm | 98.7% 98.7% 86.9% 62.3% -112 dBm | 81.6% 81.6% 70.1% 47.3% -94 dBm |
| Shelby County, IL | 94.1% 94.0% 30.6% 17.3% -95 dBm | 97.7% 97.7% 78.5% 63.6% -112 dBm | 74.4% 74.4% 61.6% 41.9% -95 dBm |
| St. Clair County, IL | 98.9% 98.9% 83.9% 68.8% -94 dBm | 99.0% 98.5% 94.2% 62.1% -108 dBm | 93.0% 93.0% 88.8% 76.0% -87 dBm |
| Stark County, IL | 99.6% 99.6% 41.8% 21.6% -95 dBm | 98.5% 98.5% 77.2% 67.8% -114 dBm | 88.7% 88.7% 72.0% 36.2% -97 dBm |
| Stephenson County, IL | 99.7% 99.7% 30.1% 15.2% -96 dBm | 86.2% 85.5% 20.7% 16.0% -113 dBm | 76.8% 76.8% 61.8% 41.7% -94 dBm |
| Tazewell County, IL | 99.5% 99.5% 69.8% 59.2% -89 dBm | 99.5% 99.5% 81.7% 53.6% -112 dBm | 96.0% 96.0% 90.5% 73.2% -88 dBm |
| Union County, IL | 96.4% 96.4% 15.2% 9.4% -96 dBm | 92.1% 91.5% 71.7% 46.7% -113 dBm | 56.2% 56.2% 44.3% 26.8% -96 dBm |
| Vermilion County, IL | 96.9% 96.8% 59.2% 37.6% -93 dBm | 99.5% 99.5% 93.4% 65.5% -109 dBm | 76.4% 76.4% 59.9% 36.8% -95 dBm |
| Wabash County, IL | 98.3% 98.3% 4.6% 1.3% -94 dBm | 98.8% 98.8% 59.0% 43.5% -114 dBm | 20.7% 20.7% 9.6% 0.6% -104 dBm |
| Warren County, IL | 98.6% 98.5% 35.9% 25.5% -93 dBm | 96.4% 96.4% 52.0% 41.7% -114 dBm | 90.1% 90.1% 73.5% 45.8% -94 dBm |
| Washington County, IL | 99.3% 99.3% 25.9% 12.7% -92 dBm | 99.2% 99.2% 91.5% 69.9% -111 dBm | 78.9% 78.9% 68.9% 49.6% -93 dBm |
| Wayne County, IL | 97.1% 97.0% 19.8% 11.1% -96 dBm | 98.2% 98.2% 62.5% 55.4% -114 dBm | 47.2% 47.1% 38.1% 21.2% -96 dBm |
| White County, IL | 98.9% 98.9% 19.3% 9.3% -95 dBm | 98.2% 98.2% 68.2% 53.5% -114 dBm | 59.0% 59.0% 42.0% 25.3% -97 dBm |
| Whiteside County, IL | 99.8% 99.8% 47.3% 25.3% -96 dBm | 98.1% 98.0% 44.2% 32.8% -112 dBm | 91.3% 91.3% 83.9% 65.5% -90 dBm |
| Will County, IL | 100.0% 100.0% 99.5% 90.5% -88 dBm | 99.7% 99.7% 94.2% 79.8% -107 dBm | 99.1% 99.1% 97.6% 91.5% -82 dBm |
| Williamson County, IL | 99.5% 99.5% 35.0% 24.7% -93 dBm | 97.7% 97.7% 79.7% 49.3% -111 dBm | 67.0% 67.0% 56.9% 41.0% -92 dBm |
About The Coverage Data
Coverage and signal estimates are derived by Compare Wireless Carriers from carrier-reported data in the FCC’s National Broadband Coverage Map, last updated in June 2025. “Percent covered” shows how much of the city or ZIP code area has a carrier signal, whether weak or strong. Signal bars show the estimated average signal strength in areas of Illinois where that carrier has coverage.
If a carrier says you should have service but you do not, run a challenge test with the FCC Mobile Speed Test App. The FCC uses those results to check carrier-submitted coverage data and requires a carrier response when enough tests show a pattern of inaccurate coverage reporting.