In San Marcos there are 3 residential Fiber providers covering 33.93% of the city. The average home can get speeds up to 4,372 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 Fiber 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
Fiber 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 fiber internet available?
Fiber Internet Availability Key
Fiber is available in 33.93% of San Marcos. Areas in green have fiber 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 fiber internet in San Marcos?
The map below shows maximum fiber internet speeds by area in San Marcos.
Fiber Internet Speed Key
The average San Marcos home can get up to 4,372 Mbps on their fiber internet plan. The fastest fiber download speed in the city is 5,000 Mbps, which 28.55% of residents can get. Some homes and apartments do not have access to these speeds. On the slower end, for example, 5.16% of homes can only purchase plans up to 1,000 Mbps. See the internet provider details below for info about their speed and coverage in San Marcos.
Fiber internet speeds tend to be faster in the north parts of San Marcos, and slower in the northwest areas of the city.
Is fiber 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 fiber 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.
Fiber 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.
EarthLink Fiber in San Marcos, CA
EarthLink fiber coverage
About 33.24%, or 34,812 people, have EarthLink fiber 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 a small portion of San Marcos.
EarthLink fiber download speeds
EarthLink is one of the fastest when comparing download speeds to all other internet providers in San Marcos. Versus other fiber providers in the area, EarthLink fiber is one of the fastest. There are 2 different maximum speeds throughout San Marcos. The fastest plan anyone in San Marcos can order from EarthLink goes up to 5,000 Mbps, the slowest package only goes up to 1,000 Mbps, and the city-wide average maximum speed for San Marcos customers is up to 4,435 Mbps.
Show all download speeds
- 85.9% up to 5,000.0 Mbps
- 14.1% up to 1,000.0 Mbps
EarthLink fiber upload speeds
In San Marcos download speeds tend to be equal to than upload speeds for EarthLink fiber. Compared to other ISPs, EarthLink is one of the fastest where upload speeds are concerned, and one of the fastest compared to other San Marcos fiber 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 San Marcos is up to 5,000 Mbps. Some customers have slower plan choices, which only go up to 1,000 Mbps. On average, EarthLink customers can get speeds up to 4,435 Mbps.
Show all upload speeds
- 85.9% up to 5,000.0 Mbps
- 14.1% up to 1,000.0 Mbps
AT&T Fiber in San Marcos, CA
AT&T fiber coverage
About 33.24%, or 34,812 people, have AT&T fiber 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 a small portion of San Marcos.
AT&T fiber download speeds
AT&T is one of the fastest when comparing download speeds to all other internet providers in San Marcos. Versus other fiber providers in the area, AT&T fiber is one of the fastest. There are 2 different maximum speeds throughout San Marcos. The fastest plan anyone in San Marcos can order from AT&T goes up to 5,000 Mbps, the slowest package only goes up to 1,000 Mbps, and the city-wide average maximum speed for San Marcos customers is up to 4,435 Mbps.
Show all download speeds
- 85.9% up to 5,000.0 Mbps
- 14.1% up to 1,000.0 Mbps
AT&T fiber upload speeds
In San Marcos download speeds tend to be equal to than upload speeds for AT&T fiber. Compared to other ISPs, AT&T is one of the fastest where upload speeds are concerned, and one of the fastest compared to other San Marcos fiber 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 San Marcos is up to 5,000 Mbps. Some customers have slower plan choices, which only go up to 1,000 Mbps. On average, AT&T customers can get speeds up to 4,435 Mbps.
Show all upload speeds
- 85.9% up to 5,000.0 Mbps
- 14.1% up to 1,000.0 Mbps
Cox Communications Fiber in San Marcos, CA
Cox fiber coverage
About 10.42%, or 10,918 people, have Cox fiber internet available to them in the city. The company covers the north, south, central, east, northeast, and southeast San Marcos area. Cox is one of the largest internet service providers internet service providers in the US, with internet service available in a very small piece of San Marcos.
Cox Communications fiber download speeds
Cox is above average when comparing download speeds to all other internet providers in San Marcos. Versus other fiber providers in the area, Cox fiber is the slowest. There are 2 different maximum speeds throughout San Marcos. The fastest plan anyone in San Marcos can order from Cox goes up to 2,000 Mbps, the slowest package only goes up to 1,000 Mbps, and the city-wide average maximum speed for San Marcos customers is up to 1,553 Mbps.
Show all download speeds
- 55.3% up to 2,000.0 Mbps
- 44.7% up to 1,000.0 Mbps
Cox Communications fiber upload speeds
In San Marcos download speeds tend to be faster than than upload speeds for Cox fiber. Compared to other ISPs, Cox is below average where upload speeds are concerned, and the slowest compared to other San Marcos fiber providers. Cox offers no different upload speeds across the city. The fastest upload speed available to anyone from this ISP in San Marcos is up to 100 Mbps, which is available to everyone covered.
Show all upload speeds
- 100.0% up to 100.0 Mbps
San Marcos Fiber 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 fiber internet in San Marcos compare to the rest of California?
Fiber internet speeds in San Marcos are much faster versus the average speeds in California: 0.00 Mbps in California versus 4,372 Mbps in the city. The state has similar fiber availability compared to the city. Average fiber coverage in California is 0.00% versus 33.93% in San Marcos.
What zip codes have fiber internet?
Fiber 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 fiber 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 fiber coverage, slower speeds
- Escondido, CA: less fiber coverage, faster speeds
- Carlsbad, CA: more fiber coverage, slower speeds
- Sunny Vista, CA: less fiber coverage, slower speeds
- Encinitas, CA: more fiber coverage, slower speeds
- Rancho Santa Fe, CA: more fiber coverage, slower speeds
- Cardiff By The Sea, CA: more fiber coverage, slower speeds
- Oceanside, CA: less fiber coverage, slower speeds
- Bonsall, CA: less fiber coverage, slower speeds
- Valley Center, CA: less fiber coverage, faster speeds
Cities with Similar Populations
- Clinton Township, MI: more fiber coverage, slower speeds
- Clayton, NC: more fiber coverage, slower speeds
- Cheyenne, WY: more fiber coverage, faster speeds
- Carolina, PR: more fiber coverage, slower speeds
- Cedar Park, TX: more fiber coverage, slower speeds
- Chino, CA: more fiber coverage, faster speeds
- Chino Hills, CA: more fiber coverage, faster speeds
- Caldwell, ID: more fiber coverage, faster speeds
- Centennial, CO: more fiber coverage, slower speeds
- Canton, OH: more fiber coverage, slower speeds