In San Marcos there are 2 residential DSL providers covering 88.89% of the city. The average home can get speeds up to 86 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 San Marcos, CA.
To see availability maps for all providers including fiber, cable, DSL, and more in San Marcos, CA please click below.
San Marcos, CA Availability Maps
DSL Internet Service Providers in San Marcos
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 San Marcos are not shown.
San Marcos 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 San Marcos is DSL internet available?
DSL Internet Availability Key
DSL is available in 88.89% of San Marcos. 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 San Marcos above to see who has service at your home.
How fast is DSL internet in San Marcos?
The map below shows maximum DSL internet speeds by area in San Marcos.
DSL Internet Speed Key
The average San Marcos home can get up to 86 Mbps on their DSL internet plan. The fastest DSL download speed in the city is 100 Mbps, which 63.36% of residents can get. Some homes and apartments do not have access to these speeds. On the slower end, for example, 3.93% of homes can only purchase plans up to 10 Mbps. See the internet provider details below for info about their speed and coverage in San Marcos.
DSL internet speeds tend to be faster in the northwest parts of San Marcos, and slower in the central areas of the city.
Is DSL the fastest internet I can get in San Marcos?
The fastest internet for you may vary based on where in San Marcos you live. In general, cable competes most often with DSL in the city.
- Fiber is the fastest internet type for 29.02% of San Marcos homes.
- Cable is fastest for 68.64% of the city.
- DSL is fastest for less than 1%.
- Fixed wireless is fastest for 1.57%.
- Satellite internet may be the only option for less than 1% of San Marcos homes.
DSL Providers in Depth
Below you'll find which TV and internet providers offer service in San Marcos, along with details on where in San Marcos and at what speeds.
AT&T DSL in San Marcos, CA
AT&T DSL coverage
About 88.89%, or 93,096 people, have AT&T DSL internet available to them in the city. The company covers the entire San Marcos area. AT&T is one of the largest internet service providers internet service providers in the US, with internet service available in most of San Marcos.
AT&T DSL download speeds
AT&T is below average when comparing download speeds to all other internet providers in San Marcos. Versus other DSL providers in the area, AT&T DSL is one of the fastest. There are 5 different maximum speeds throughout San Marcos. The fastest plan anyone in San Marcos can order from AT&T goes up to 100 Mbps, the slowest package only goes up to 10 Mbps, and the city-wide average maximum speed for San Marcos customers is up to 86 Mbps.
Show all download speeds
- 71.3% up to 100.0 Mbps
- 11.5% up to 75.0 Mbps
- 10.9% up to 50.0 Mbps
- 1.8% up to 25.0 Mbps
- 4.4% up to 10.0 Mbps
AT&T DSL upload speeds
In San Marcos download speeds tend to be faster than than upload speeds for AT&T DSL. Compared to other ISPs, AT&T is below average where upload speeds are concerned, and one of the fastest compared to other San Marcos DSL providers. AT&T offers 4 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 San Marcos is up to 20 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 18 Mbps.
Show all upload speeds
- 82.8% up to 20.0 Mbps
- 10.9% up to 10.0 Mbps
- 1.8% up to 5.0 Mbps
- 4.4% up to 1.0 Mbps
EarthLink DSL in San Marcos, CA
EarthLink DSL coverage
About 88.89%, or 93,096 people, have EarthLink DSL internet available to them in the city. The company covers the entire San Marcos area. EarthLink is one of the largest internet service providers internet service providers in the US, with internet service available in most of San Marcos.
EarthLink DSL download speeds
EarthLink is below average when comparing download speeds to all other internet providers in San Marcos. Versus other DSL providers in the area, EarthLink DSL is one of the fastest. There are 5 different maximum speeds throughout San Marcos. The fastest plan anyone in San Marcos can order from EarthLink goes up to 100 Mbps, the slowest package only goes up to 10 Mbps, and the city-wide average maximum speed for San Marcos customers is up to 86 Mbps.
Show all download speeds
- 71.3% up to 100.0 Mbps
- 11.5% up to 75.0 Mbps
- 10.9% up to 50.0 Mbps
- 1.8% up to 25.0 Mbps
- 4.4% up to 10.0 Mbps
EarthLink DSL upload speeds
In San Marcos download speeds tend to be faster than than upload speeds for EarthLink DSL. Compared to other ISPs, EarthLink is below average where upload speeds are concerned, and one of the fastest compared to other San Marcos DSL providers. EarthLink offers 4 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 San Marcos is up to 20 Mbps. Some customers have slower plan choices, which only go up to 1.0 Mbps. On average, EarthLink customers can get speeds up to 18 Mbps.
Show all upload speeds
- 82.8% up to 20.0 Mbps
- 10.9% up to 10.0 Mbps
- 1.8% up to 5.0 Mbps
- 4.4% up to 1.0 Mbps
San Marcos DSL by Area
This information is most helpful to those looking for homes or considering moving to San Marcos or any of the areas nearby.
How does DSL internet in San Marcos compare to the rest of California?
DSL internet speeds in San Marcos are much faster versus the average speeds in California: 0.00 Mbps in California versus 86 Mbps in the city. The state has similar DSL availability compared to the city. Average DSL coverage in California is 0.00% versus 88.89% in San Marcos.
What zip codes have DSL internet?
DSL internet coverage varies by zip code and neighborhood. Some examples in or around San Marcos 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
- Vista, CA: more DSL coverage, faster speeds
- Escondido, CA: more DSL coverage, faster speeds
- Carlsbad, CA: more DSL coverage, faster speeds
- Sunny Vista, CA: less DSL coverage, faster speeds
- Encinitas, CA: more DSL coverage, faster speeds
- Rancho Santa Fe, CA: less DSL coverage, slower speeds
- Cardiff By The Sea, CA: more DSL coverage, faster speeds
- Oceanside, CA: less DSL coverage, faster speeds
- Bonsall, CA: less DSL coverage, slower speeds
- Valley Center, CA: less DSL coverage, slower speeds
Cities with Similar Populations
- Clinton Township, MI: more DSL coverage, slower speeds
- Clayton, NC: less DSL coverage, slower speeds
- Cheyenne, WY: more DSL coverage, slower speeds
- Carolina, PR: less DSL coverage, slower speeds
- Cedar Park, TX: less DSL coverage, slower speeds
- Chino Hills, CA: less DSL coverage, slower speeds
- Caldwell, ID: more DSL coverage, slower speeds
- Centennial, CO: more DSL coverage, faster speeds
- Canton, OH: less DSL coverage, slower speeds
- Camarillo, CA: less DSL coverage, slower speeds