In Port Costa there are 2 residential DSL providers covering 83.33% of the city. The average home can get speeds up to 21 Mbps. Note that we may have a financial relationship with some of the providers below. This does not influence rankings, and helps us provide high-quality detailed information for free.
This page contains all DSL internet providers in Port Costa, CA.
To see availability maps for all providers including fiber, cable, DSL, and more in Port Costa, CA please click below.
Port Costa, CA Availability Maps
DSL Internet Service Providers in Port Costa
Data updated 11/14/2025, based on FCC data from 12/31/2024. This is the most current data available as of .
To avoid wasting your time, providers with less than 1% coverage in Port Costa are not shown.
Port Costa Satellite TV & Internet Providers
DISH Satellite TV
DIRECTV Satellite TV
Not sure whether to choose Dish or DIRECTV? For most people most of the time we recommend DISH. But click here to learn more.
Viasat Satellite Internet
Where in Port Costa is DSL internet available?
DSL Internet Availability Key
DSL is available in 83.33% of Port Costa. Areas in green have DSL internet service, where areas in yellow or red may not. The most widely available provider is AT&T. Call one of the companies with service in Port Costa above to see who has service at your home.
How fast is DSL internet in Port Costa?
The map below shows maximum DSL internet speeds by area in Port Costa.
DSL Internet Speed Key
The average Port Costa home can get up to 21 Mbps on their DSL internet plan. The fastest DSL download speed in the city is 50 Mbps, which 23.27% of residents can get. Some homes and apartments do not have access to these speeds. On the slower end, for example, 60.06% of homes can only purchase plans up to 10 Mbps. See the internet provider details below for info about their speed and coverage in Port Costa.
DSL internet speeds tend to be faster in the northwest parts of Port Costa, and slower in the east areas of the city.
Is DSL the fastest internet I can get in Port Costa?
The fastest internet for you may vary based on where in Port Costa you live. In general, cable competes most often with DSL in the city.
- Fiber is the fastest internet type for less than 1% of Port Costa homes.
- Cable is fastest for 83.02% of the city.
- DSL is fastest for less than 1%.
- Fixed wireless is fastest for 10.69%.
- Satellite internet may be the only option for 5.97% of Port Costa homes.
DSL Providers in Depth
Below you'll find which TV and internet providers offer service in Port Costa, along with details on where in Port Costa and at what speeds.
AT&T DSL in Port Costa, CA
AT&T DSL coverage
About 83.33%, or 265 people, have AT&T DSL internet available to them in the city. The company covers the east, central, northwest, and north Port Costa area. AT&T is one of the largest internet service providers internet service providers in the US, with internet service available in much of Port Costa.
AT&T DSL download speeds
AT&T is one of the slowest when comparing download speeds to all other internet providers in Port Costa. Versus other DSL providers in the area, AT&T DSL is one of the fastest. There are 2 different maximum speeds throughout Port Costa. The fastest plan anyone in Port Costa can order from AT&T goes up to 50 Mbps, the slowest package only goes up to 10 Mbps, and the city-wide average maximum speed for Port Costa customers is up to 21 Mbps.
Show all download speeds
- 27.9% up to 50.0 Mbps
- 72.1% up to 10.0 Mbps
AT&T DSL upload speeds
In Port Costa download speeds tend to be faster than than upload speeds for AT&T DSL. Compared to other ISPs, AT&T is average where upload speeds are concerned, and one of the fastest compared to other Port Costa DSL providers. AT&T offers 2 different upload speeds across the city, so your internet plan's upload speed may vary by neighborhood . The fastest upload speed available to anyone from this ISP in Port Costa is up to 10 Mbps. Some customers have slower plan choices, which only go up to 1.0 Mbps. On average, AT&T customers can get speeds up to 3.5 Mbps.
Show all upload speeds
- 27.9% up to 10.0 Mbps
- 72.1% up to 1.0 Mbps
EarthLink DSL in Port Costa, CA
EarthLink DSL coverage
About 83.33%, or 265 people, have EarthLink DSL internet available to them in the city. The company covers the east, central, northwest, and north Port Costa area. EarthLink is one of the largest internet service providers internet service providers in the US, with internet service available in much of Port Costa.
EarthLink DSL download speeds
EarthLink is one of the slowest when comparing download speeds to all other internet providers in Port Costa. Versus other DSL providers in the area, EarthLink DSL is one of the fastest. There are 2 different maximum speeds throughout Port Costa. The fastest plan anyone in Port Costa can order from EarthLink goes up to 50 Mbps, the slowest package only goes up to 10 Mbps, and the city-wide average maximum speed for Port Costa customers is up to 21 Mbps.
Show all download speeds
- 27.9% up to 50.0 Mbps
- 72.1% up to 10.0 Mbps
EarthLink DSL upload speeds
In Port Costa download speeds tend to be faster than than upload speeds for EarthLink DSL. Compared to other ISPs, EarthLink is average where upload speeds are concerned, and one of the fastest compared to other Port Costa DSL providers. EarthLink offers 2 different upload speeds across the city, so your internet plan's upload speed may vary by neighborhood . The fastest upload speed available to anyone from this ISP in Port Costa is up to 10 Mbps. Some customers have slower plan choices, which only go up to 1.0 Mbps. On average, EarthLink customers can get speeds up to 3.5 Mbps.
Show all upload speeds
- 27.9% up to 10.0 Mbps
- 72.1% up to 1.0 Mbps
Port Costa DSL by Area
This information is most helpful to those looking for homes or considering moving to Port Costa or any of the areas nearby.
How does DSL internet in Port Costa compare to the rest of California?
DSL internet speeds in Port Costa are much faster versus the average speeds in California: 0.00 Mbps in California versus 21 Mbps in the city. The state has similar DSL availability compared to the city. Average DSL coverage in California is 0.00% versus 83.33% in Port Costa.
What zip codes have DSL internet?
DSL internet coverage varies by zip code and neighborhood. Some examples in or around Port Costa are shown below. You can enter any zip code here to see TV and internet providers by zip code.
What does DSL internet look like in other cities?
Below are cities nearby and with similar populations. This comparison can be useful if living somewhere with fast internet is important to you.
Nearby Cities
- Crockett, CA: less DSL coverage, slower speeds
- Benicia, CA: more DSL coverage, faster speeds
- Tormey, CA: more DSL coverage, faster speeds
- Rodeo, CA: more DSL coverage, faster speeds
- Hercules, CA: more DSL coverage, faster speeds
- Vallejo, CA: more DSL coverage, faster speeds
- Martinez, CA: more DSL coverage, faster speeds
- Pinole, CA: more DSL coverage, faster speeds
- El Sobrante, CA: more DSL coverage, faster speeds
- Reliez Valley, CA: less DSL coverage, faster speeds
Cities with Similar Populations
- Concord, NE: less DSL coverage, slower speeds
- Clopton, AL: less DSL coverage, faster speeds
- Cloverland, IN: more DSL coverage, faster speeds
- Clymers, IN: more DSL coverage, faster speeds
- Coalton, IL: more DSL coverage, faster speeds
- Coalville, NC: less DSL coverage, faster speeds
- Cobalt, ID: more DSL coverage, slower speeds
- Coburg, KY: more DSL coverage, faster speeds
- Coffey, MO: more DSL coverage, faster speeds
- Colbert Heights, AL: less DSL coverage, faster speeds