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DSDownloadSpeed
FCC Data · Updated April 2026
A

Corson County Internet

Corson County, South Dakota has a Broadband Grade of A with an average download speed of 1000 Mbps across 11 ZIP codes. 100% of the county has fiber internet access, and the area averages 10 providers per ZIP code. Internet access is above average for the U.S.

99
Score
1000 Mbps
Avg Download
100%
Fiber Access
10
Avg Providers
Grade Distribution

ZIP Code Grades in Corson County

A
11
B
0
C
0
D
0
F
0
Best

Fastest ZIP Codes in Corson County

ZIPGradeDownloadProvidersFiber
57621A1000 Mbps10Yes
57633A1000 Mbps10Yes
57634A1000 Mbps10Yes
57639A1000 Mbps10Yes
57641A1000 Mbps10Yes
57642A1000 Mbps10Yes
57645A1000 Mbps10Yes
57657A1000 Mbps10Yes
57658A1000 Mbps10Yes
57659A1000 Mbps10Yes
Needs Improvement

Slowest ZIP Codes in Corson County

ZIPGradeDownloadProvidersFiber
57621A1000 Mbps10Yes
57633A1000 Mbps10Yes
57634A1000 Mbps10Yes
57639A1000 Mbps10Yes
57641A1000 Mbps10Yes
57642A1000 Mbps10Yes
57645A1000 Mbps10Yes
57657A1000 Mbps10Yes
57658A1000 Mbps10Yes
57659A1000 Mbps10Yes
FAQ

Frequently Asked Questions

What is the average internet speed in Corson County, South Dakota?

Corson County, South Dakota has an average maximum download speed of 1000 Mbps across 11 ZIP codes. The county received a Broadband Grade of A (99/100), which factors in download speed, provider competition, fiber availability, and upload speed. This meets the FCC broadband standard of 100 Mbps download.

How many internet providers are in Corson County?

Corson County has an average of 10 internet providers per ZIP code. 100% of ZIP codes in the county have fiber internet access. Having 3 or more providers typically leads to better prices and service quality through competition.

Is there fiber internet in Corson County?

100% of ZIP codes in Corson County, South Dakota have fiber internet available. Fiber provides the fastest and most reliable connections, typically 500 Mbps to 5 Gbps with symmetrical upload speeds. Fiber coverage in this county is above the national average.

What is the best ZIP code for internet in Corson County?

The best-connected ZIP code in Corson County is 57621 with a Broadband Grade of A, 1000 Mbps maximum download, and 10 providers. Fiber internet is available in this ZIP code.

Test Your Speed

See how your connection compares to Corson County's 1000 Mbps average.