Best Internet in St. Clair, IL
1000 Mbps avg · 27 ZIP codes · 100% fiber · 10 providers/ZIP
Internet Providers in St. Clair
| Provider | ZIP Codes Served | % of Area |
|---|---|---|
| Comcast | 27 | 100% |
| At&T Illinois | 27 | 100% |
| T-Mobile | 27 | 100% |
| King Street L.p. | 27 | 100% |
| United States Cellular Corporation | 27 | 100% |
| Rise Broadband | 27 | 100% |
| Frontier North Illinois Gte | 27 | 100% |
| Wisper Isp, LLC | 27 | 100% |
ZIP Codes in St. Clair
See how your connection compares to the 1000 Mbps average in St. Clair.
Frequently Asked Questions
What is the average internet speed in St. Clair, IL?
St. Clair, Illinois has an average maximum download speed of 1000 Mbps across 27 ZIP codes. The fastest available speed is 1000 Mbps. 100% of ZIP codes have fiber internet.
Who are the best internet providers in St. Clair?
The most widely available providers in St. Clair are Comcast (27 ZIPs), At&T Illinois (27 ZIPs), T-Mobile (27 ZIPs). Check individual ZIP codes for exact availability at your address.
Is fiber internet available in St. Clair?
Yes, fiber internet is available in 100% of St. Clair's ZIP codes. Fiber coverage is good in this area. Search your specific ZIP code for exact fiber availability.
How does St. Clair compare to the rest of Illinois?
St. Clair has an average Broadband Grade of B (71/100). The St. Clair area averages 10 providers per ZIP code with 100% fiber access. Check the Illinois overview for statewide comparison.
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.
The methodology behind every numeric value on this page is publicly documented on the the FCC Broadband Data Collection (BDC) portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for this entity’s peers within U.S. ZIPs, counties, and states. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.
Source: FCC Broadband Data Collection, 2026.