Illinois Internet Overview
825 Mbps avg · 1396 ZIP codes · 98% fiber · 102 counties
County Grade Distribution
Best Broadband Counties in Illinois
| County | Grade | Avg Download | Fiber | ZIPs |
|---|---|---|---|---|
| DeKalb | A | 1000 Mbps | 100% | 13 |
| Kendall | A | 1000 Mbps | 100% | 8 |
| McDonough | A | 1000 Mbps | 100% | 10 |
| McLean | A | 1000 Mbps | 100% | 24 |
| Adams | A | 1000 Mbps | 100% | 16 |
| Clay | A | 1000 Mbps | 100% | 7 |
| Brown | A | 1000 Mbps | 100% | 3 |
| Wabash | A | 1000 Mbps | 100% | 4 |
| Fulton | A | 1000 Mbps | 100% | 20 |
| Kane | A | 1000 Mbps | 100% | 22 |
| Richland | A | 1000 Mbps | 100% | 6 |
| Warren | A | 1000 Mbps | 100% | 8 |
| Christian | A | 1000 Mbps | 100% | 14 |
| Tazewell | A | 1000 Mbps | 100% | 16 |
| Hancock | A | 1000 Mbps | 100% | 16 |
Slowest Counties in Illinois
| County | Grade | Avg Download | Fiber | ZIPs |
|---|---|---|---|---|
| Fayette | D | 1000 Mbps | 100% | 9 |
| Cass | C | 1000 Mbps | 100% | 6 |
| Menard | C | 1000 Mbps | 100% | 5 |
| Calhoun | C | 1000 Mbps | 100% | 6 |
| Cumberland | C | 1000 Mbps | 100% | 5 |
| Greene | C | 1000 Mbps | 100% | 10 |
| Washington | C | 100 Mbps | 100% | 10 |
| Clark | C | 100 Mbps | 100% | 7 |
| Bond | C | 100 Mbps | 100% | 8 |
| Union | C | 100 Mbps | 100% | 7 |
| Massac | C | 100 Mbps | 100% | 5 |
| Putnam | C | 100 Mbps | 100% | 7 |
| Marshall | C | 1000 Mbps | 100% | 8 |
| Perry | C | 1000 Mbps | 100% | 6 |
| Carroll | C | 1000 Mbps | 100% | 7 |
All 102 Counties in Illinois
Internet Providers in Illinois
| Provider | ZIP Codes | Max Speed |
|---|---|---|
| T-Mobile | 1,396 | 25 Mbps |
| Comcast (Xfinity) | 1,396 | 2,000 Mbps |
| AT&T | 1,396 | 1,000 Mbps |
| United States Cellular Corporation | 1,396 | 2 Mbps |
| Frontier Communications | 1,396 | 1,000 Mbps |
| King Street L.p. | 1,396 | 10 Mbps |
| Rise Broadband | 1,396 | 250 Mbps |
| Wisper Isp, LLC | 1,396 | 100 Mbps |
Cities in Illinois
Neighboring States
See how your connection compares to the 825 Mbps average in Illinois.
Frequently Asked Questions
What is the average internet speed in Illinois?
Illinois has an average maximum download speed of 825 Mbps across 1396 ZIP codes. 98% of areas have fiber internet access, and the state averages 10 providers per ZIP code.
Which counties in Illinois have the best internet?
The counties with the best broadband in Illinois include DeKalb (Grade A), Kendall (Grade A), McDonough (Grade A). These areas have the fastest average speeds and most provider competition.
How does Illinois compare to the national average?
The national average download speed is 876 Mbps, while Illinois averages 825 Mbps, below the national average. Nationally, 96% of areas have fiber, compared to 98% in Illinois.
For this entity, the underlying data on this page comes from the FCC Broadband Data Collection (BDC). The breakdown above is the federal record; the paragraphs below add the per-entity context that makes the headline numbers usable for a real decision rather than just a data lookup.
Every number on this page links back to the FCC Broadband Data Collection (BDC); the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. ZIPs, counties, and states with similar size, similar exposure, or similar geography — not the national-level summary alone.
Source: FCC Broadband Data Collection, 2026.