Internet in San Mateo, California

Three wires at most addresses

The FCC counts 23,468 homes and businesses in San Mateo, and its June 30, 2026 data (file revision of November 10, 2026) show three wired networks reaching nearly all of them. Xfinity reports service, almost all of it cable, at 99.2% of locations, AT&T reports service at 95.7%, mostly over fiber, and Astound, the second cable company, at 88.4%. Where all three overlap, a home has three wired providers offering 100/20 Mbps or faster. Three or more such providers are reported at 81.7% of San Mateo's locations, the 7th highest share among the 343 US cities of 100,000 or more; the national figure is 11.1%¹.

NoneOneTwoThree or more

San Mateo

Daly City

California

United States

Source: FCC, National Broadband Map, data as of June 30, 2026. Different wired providers (fiber, cable or DSL; FCC provider IDs) reporting 100 Mbps down and 20 Mbps up or more at the same location. Fixed wireless and satellite are not counted.

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Area	None	One	Two	Three or more
San Mateo	0.2%	4.1%	14.1%	81.7%
Daly City	0.1%	10.1%	34.2%	55.6%
California	6.9%	43.2%	43.4%	6.5%
United States	7.8%	36.6%	44.6%	11.1%

A share in the table is the part of the city's locations where a company says it serves customers or could install standard service within ten business days. These are the providers' own filings, open to challenge on the FCC National Broadband Map, which is also where one address can be checked. This page covers the city of San Mateo within its 2020 Census limits, not San Mateo County.

Fiber: AT&T at most locations, Sonic at a third

Fiber from at least one provider reaches 88.3% of locations, the 89th highest share among large US cities and well above California's 47.8%. Most of it is AT&T's: the company reports fiber at 81.5% of locations, with advertised downloads up to 5 Gbps. Sonic, a fiber company whose FCC filings are almost entirely in California, covers 34.4% of San Mateo's locations and advertises up to 10 Gbps¹.

Where those footprints overlap, a location has two or more fiber providers. That share is 28.5%, up from 22.6%² in June 2022, against 5.8% statewide. Daly City, farther up the Peninsula, has fiber at 76.9% of locations but two or more fiber networks at only 1.9%¹.

Berkeley91.6%

Oakland90.1%

San Mateo88.3%

Daly City76.9%

United States62.6%

San Francisco60.8%

California47.8%

Source: FCC, National Broadband Map, data as of June 30, 2026. FCC file revision of November 10, 2026. Shares are of broadband serviceable locations (homes and businesses), not people.

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Area	Fiber available
Berkeley	91.6%
Oakland	90.1%
San Mateo	88.3%
Daly City	76.9%
United States	62.6%
San Francisco	60.8%
California	47.8%

Few places with one wire or none

The other side of the overlap is how rarely a home depends on one company. Only 4.1% of locations have a single wired provider at 100/20 Mbps, the 22nd lowest share among large cities; Xfinity is that single provider at 3.9%. In Daly City, by comparison, 55.6%¹ of locations have three or more wired choices.

At the far end, the FCC data list 45 locations with no wired provider at 100/20 Mbps. Of those, 9 have that speed only by fixed wireless, and 1 location depends on satellite alone. Under the BEAD program's definitions, 5¹ locations in the city are unserved.

Fixed wireless: two carriers and a regional network

6 companies report licensed fixed wireless home internet in San Mateo, four of them across much of the city. Verizon reports it at 80.5% of locations and offers 100/20 Mbps at 33.4%; T-Mobile reports 71.8%, with 100/20 at 27.7%. Etheric Networks, a radio network that files only in California, reports 100/20 Mbps at 66.5%, and Unwired at 22.4%¹.

Licensed fixed wireless at 100/20 Mbps is reported at 81.4% of locations, up from 9.4%² in 2022 and the 38th highest¹ share among large cities. A tower sector's capacity is shared, so carriers decide address by address whether to accept new customers; the FCC figures show where service is reported, not how many homes could sign up at once.

Since 2022: copper out, faster tiers in

The biggest change in San Mateo since the first map release is not new coverage but what the existing networks report. DSL over copper telephone lines was reported at 31.5%² of locations in June 2022 and at 21.4% by June 2026, a fall of 10.1 percentage points, while fiber rose by 3.5 percentage points¹.

June 30, 2022December 31, 2025June 30, 2026

DSL available21.4% −10.1 pts

Gigabit (1,000/100)99.4% +14.6 pts

2 Gbps or more99.2% +56.2 pts

Two or more fiber networks28.5% +5.8 pts

Source: FCC, National Broadband Map, data as of June 30, 2022; FCC, National Broadband Map, data as of December 31, 2025; FCC, National Broadband Map, data as of June 30, 2026. Shares of broadband serviceable locations in each FCC release (latest revision of each); the small number is the change in percentage points since June 30, 2022. The FCC's count of locations is updated with each release, so shares are compared rather than counts.

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Measure	June 30, 2022	December 31, 2025	June 30, 2026	Change (points)
DSL available	31.5%	21.5%	21.4%	−10.1 pts
Gigabit (1,000/100)	84.8%	99.5%	99.4%	14.6 pts
2 Gbps or more	43.0%	99.2%	99.2%	56.2 pts
Two or more fiber networks	22.6%	28.3%	28.5%	5.8 pts

Advertised speed tiers moved up at the same time. The share of locations offered gigabit service with uploads of at least 100 Mbps (the FCC's 1,000/100 tier) went from 84.8% to 99.4%, a gain much larger than fiber's, and the share whose fastest advertised download is 2 Gbps or more went from 43.0%² to 99.2%. Astound advertises up to 1.5 Gbps; Xfinity's top figure, 2 Gbps, applies only where it has fiber, at 0.1%¹ of locations. All of these are advertised maximums from the providers' filings, not measured speeds.

Subscriptions: online almost everywhere, more by phone only

The Census Bureau's 2025 survey found 97.3% of San Mateo households with a broadband subscription of some kind (margin of error ±1.7 percentage points), up from 93.5% in 2019 (margin ±2.5 percentage points⁵). Wired subscriptions to cable, fiber or DSL stood at 79.2% (margin ±3.6 percentage points⁴), lower than the three-wire coverage might suggest.

Wired 100/20 Mbps available (FCC, share of locations)99.8%

Households subscribing to cable, fiber or DSL (Census)79.2% ±3.6

Households relying only on a cellular data plan17.0% ±4.2

Households with no internet subscription2.7% ±1.6

Source: FCC, National Broadband Map, data as of June 30, 2026; Census Bureau, American Community Survey 2025 1-year detailed tables. Availability is a share of locations as of June 30, 2026 (FCC); subscriptions are a share of households from the American Community Survey, 2025 (whiskers: 90% margin of error). Different units and dates: read the gap as a sign, not an exact number.

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Measure	Share	MOE
Wired 100/20 Mbps available (FCC, share of locations)	99.8%
Households subscribing to cable, fiber or DSL (Census)	79.2%	±3.6
Households relying only on a cellular data plan	17.0%	±4.2
Households with no internet subscription	2.7%	±1.6

The difference sits mostly with phone plans. Households relying only on a cellular data plan were 17.0% (margin ±4.2 percentage points), the 37th highest⁴ share among large cities by point estimate, against 9.5% in 2019 (margin ±2.9 percentage points⁵); the two ranges do not overlap. These are survey estimates of households over a year, while the FCC figures count locations on one date.

San Mateo beside cities its size

The table puts San Mateo beside the cities closest to it in population, all from the same FCC release.

The California page maps every county, including San Mateo County, where the city sits between San Francisco and the cities of Silicon Valley.