Mobile data island by island in Cape Verde: what the regulator measured on Sal, Boa Vista, Santiago and the rest

Part of our Cape Verde eSIM guide: all articles and key facts →

An eSIM for Cape Verde works on every inhabited island, but the signal and the speed are not the same on Sal as on Santo Antão. This island guide uses the only island-by-island measurements we found: the 2025 drive tests of the national regulator, which compared the two networks, Unitel T+ and Alou, on all nine inhabited islands.

Which network works best on each island?

Alou had the higher average download speed on all nine islands, while signal availability was close between the two networks except on Santo Antão and Brava, where Unitel T+ had no signal in 12% and 10% of the measurements. The figures below come from the 283-page quality and coverage report of the ARME (Agência Reguladora Multissectorial da Economia), dated November 2025 and published on 2 March 2026.

"Signal on route" is the share of measurements where the phone had a network signal. "Data access" is the share of data tests where the phone managed to reach the service at all. The averages are for the island as a whole, as checked on 16 October 2026 in the published report.

How the regulator measured, and what it did not measure

The tests were drive tests: mid-range phones in a moving car, on both networks at the same time, between 08:00 and 19:00, from May to November 2025. The ARME worked with Portugal's regulator ANACOM and chose routes through the main towns, the main roads and the interior of each island, drawn on Google Earth.

Three limits matter for a traveller. The report does not measure inside buildings, so a hotel room can be worse than the street outside. It does not name beaches, airports or hiking areas. And it says nothing about 5G: it covers 2G, 3G and 4G only, and 4G was the dominant technology on every island.

The report also warns that speed depends on factors the test could not control, such as the number of people on the same mast. Treat the figures as a comparison between the two networks on the same roads, not as a promise for your exact spot.

Sal: Santa Maria, Espargos and the airport

Sal had the best coverage in the country: both networks had a signal on 100% of the route, in Espargos, in Santa Maria and in the interior. In Santa Maria, the resort town, the average download was 41.2 Mbps on Alou and 31.1 Mbps on Unitel T+. In Espargos it was 43.0 Mbps against 16.1 Mbps.

Unitel T+ was more reliable at opening a data session on Sal: 98.4% of its data tests reached the service, against 91.6% for Alou. That matters for travel eSIMs, because Airalo and Nomad name Unitel T+ as their network.

Wikipedia describes Amílcar Cabral International Airport (SID) as the main international airport of Cape Verde. Unitel T+ lists a shop inside the airport, the only airport shop on its store list, in case your eSIM fails to connect on arrival.

Boa Vista: Sal Rei and the interior

Boa Vista is the one island where Unitel T+ kept a signal more often than Alou: 99.3% of the route against 96.1%. In Sal Rei both networks had a signal everywhere on the route, with an average download of 48.0 Mbps on Alou and 25.8 Mbps on Unitel T+.

The difference showed in the interior of the island: Unitel T+ had a signal on 99% of that route against 94% for Alou, and reached the data service in 84.5% of tests against 71.6%. An older ARME test on Sal and Boa Vista, in June 2023, had already put Unitel T+ ahead on signal, according to an Inforpress report.

Flights land at Aristides Pereira International Airport (BVC). Unitel T+ lists one shop on the island, in Sal Rei.

Santiago: Praia, Assomada, Tarrafal and the roads

In Praia, the capital, both networks had a signal on 100% of the route and more than 98% of data tests reached the service. The average download was 46.0 Mbps on Alou and 24.5 Mbps on Unitel T+, and 4G carried more than 70% of the samples on both networks.

Outside the capital, the town of Tarrafal recorded 63.0 Mbps on Alou against 25.9 Mbps on Unitel T+, and Assomada was close between the two (23.1 and 20.8 Mbps). On the island's main roads both networks kept a signal on almost all the route, but Unitel T+ reached the data service in 67.4% of tests against 84.5% for Alou.

Praia's airport, Nelson Mandela International (RAI), receives international flights, according to Wikipedia's list of airports in Cape Verde.

São Vicente: Mindelo

São Vicente had near-complete coverage on both networks: 99.8% of the route, and 100% in Mindelo and in the interior. Speeds were lower than on Sal or in Praia: 23.0 Mbps on Alou and 17.0 Mbps on Unitel T+ in Mindelo.

The island's airport is Cesária Évora Airport (VXE), near Mindelo. Santo Antão, the neighbouring island, has no operating airport according to the same Wikipedia list.

Is there mobile signal on Santo Antão?

Yes in the towns, much less in the interior: on the regulator's interior route, Alou had a signal on 89% of the route and Unitel T+ on 76%. Santo Antão was the weakest island in the report. Over the whole island, Unitel T+ had no signal or a poor signal on 12.3% of the route, against 5% for Alou.

The data service was the real problem. Only 50.9% of Alou's tests and 37.4% of Unitel T+'s tests reached the service in the interior. In the towns it was better: Porto Novo had a signal on 100% of the route on both networks, and Ribeira Grande and Paul on 99% (Alou) and 94% (Unitel T+).

For hikers, the lesson is practical. Download offline maps before leaving the town, and do not count on a travel eSIM on Unitel T+ in the valleys. If you need coverage in the interior, Alou's own eSIM, which runs on the network that held up better there, is described in our comparison of an eSIM against a local Unitel T+ or Alou SIM.

Is there mobile signal on Fogo?

Yes: on Fogo, Alou had a signal on 99% of the route and Unitel T+ on 97%, but only 76.2% of all data tests on the island completed. In São Filipe both networks had full signal on the route, with 40.9 Mbps on Alou and 25.7 Mbps on Unitel T+.

In the interior of the island, data access dropped to 71.4% on Alou and 55.5% on Unitel T+. The report does not name the Chã das Caldeiras crater area, so we cannot say what the signal is like at the volcano itself. São Filipe Airport (SFL) is listed as operating.

Maio, São Nicolau and Brava

On the three smaller islands, Alou held a signal more often than Unitel T+, and Unitel T+ reached the data service less often.

• Maio: full signal on both networks in Porto Inglês; in the interior, 96% (Alou) against 89% (Unitel T+). Data access: 88.5% against 70.9%.
• São Nicolau: signal on 91.1% (Alou) and 87.9% (Unitel T+) of the route. The regulator rated the island's data success "Má" (poor): 67.60% of tests completed across both networks.
• Brava: Alou had a signal on 97.7% of the route, Unitel T+ on 90%. In Nova Sintra, Alou averaged 75.5 Mbps and Unitel T+ 6.7 Mbps. Brava has no operating airport, and Unitel T+ lists no shop there.

How did the regulator rate each island overall?

The ARME rated combined coverage "Excelente" on Sal, São Vicente, Boa Vista, Maio, Santiago (Praia) and Fogo, "Muito Bom" on Santo Antão and Brava, and "Bom" on São Nicolau. Its conclusions table pools the two networks, and gives the share of the route with a signal and the share of data tests completed:

• Sal: signal 100%, data tests completed 95.10%.
• Santiago (Praia): signal 100%, data 96.60%.
• São Vicente: signal 100%, data 95.40%.
• Boa Vista: signal 99.50%, data 86.50%.
• Maio: signal 100%, data 82.90%.
• Brava: signal 98%, data 81.60%.
• Fogo: signal 99.50%, data 76.20%.
• Santo Antão: signal 96.60%, data 71.90%.
• São Nicolau: signal 93.20%, data 67.60%, the only island where the data rating was "Má".

The gap between the two columns is the useful part. A phone can show bars and still fail to load a page: on Fogo, the signal was there almost everywhere, yet nearly a quarter of data tests did not complete.

4G or 3G: what your phone will use on each island

The regulator's summary rates 4G as the predominant technology on every island, but 3G still carried a large share of the samples, and on São Nicolau 3G led on Alou's network. The regulator gives the split by network:

• Santiago (Praia): 4G on 74.1% of Alou samples and 71.3% of Unitel T+ samples.
• São Vicente: 4G on 67.8% for Unitel T+ and 60.8% for Alou.
• Boa Vista: 4G on 62.3% for Unitel T+ and 58.8% for Alou.
• Santo Antão: 4G on 47% for Alou and 43.9% for Unitel T+, with 3G at 42.4% and 37.7%.
• São Nicolau: 4G led on Unitel T+ (43.7%), while 3G led on Alou (45.9%).

Your phone switches between 4G and 3G on its own. On 3G, pages load more slowly, so the averages above already include those moments.

Which network does your eSIM use?

Airalo and Nomad name Unitel T+ as their Cape Verde network: Airalo's Cape Verde page lists "UNITEL" and Nomad's Cape Verde page lists "Unitel T+". Yesim's own page and Saily's eSIMDB listing name no operator; eSIMDB's own data lists Yesim on CV Móvel (Alou) and Ubigi on both networks, which we could not confirm on the providers' pages. The Unitel T+ tourist eSIM runs on Unitel T+ and, in the operator's words, "works nationwide on the Unitel T+ network".

A few smaller sellers listed on eSIMDB's Cape Verde page offer a choice: ESIM.DOG, for example, sells plans routed on "T+ Telecom" and others on "Alou Cape Verde". If you will spend most of your time on Santo Antão, Maio or Brava, a plan on Alou matches the network that held a signal more often there in the 2025 tests.

The comparison of the best eSIMs for Cape Verde gives every price and plan length.

Does one eSIM work when you hop between islands?

Yes: a Cape Verde eSIM is national, so the same plan works on every island its network covers, with no extra charge for moving between them. Both networks were present on all nine islands in the regulator's tests.

Plan the hops by air or sea. Wikipedia's list shows operating airports on Sal, Boa Vista, Santiago, São Vicente, Fogo, Maio and São Nicolau; the airports of Santo Antão and Brava are listed as defunct. If your eSIM does not reconnect after a flight, toggle airplane mode, then see our fixes for an eSIM stuck on activating.

Unlimited eSIMs for Cape Verde: the real caps

Most eSIMs sold as "unlimited" for Cape Verde give a fixed amount of full-speed data per day, then slow down; among the plans we found on 16 October 2026, only Unitel T+ and Yesim did not publish a daily cap. These are the plans we found on eSIMDB and on the Unitel T+ shop:

At 512 kbps, messages and maps still work, but video calls and photo uploads become slow. Unitel T+ also limits renewals: an unlimited pack can be renewed up to two times, then you must switch to another pack. Before buying any plan, check that your phone appears in our list of eSIM-compatible phones, for example on the iPhone page or the Google Pixel page, and that it is unlocked, as our guide to unlocked phones and travel eSIMs explains.

Practical tips for weak-signal islands

• Install the eSIM at home on Wi-Fi; some shops ask for the EID, and here is how to find your EID number.
• Download offline maps for Santo Antão, Fogo and São Nicolau before leaving the towns.
• On Android, set the Cape Verde line for mobile data with our Android activation guide.
• Keep data roaming off on your home line: Cape Verde is outside the EU roaming zone.
• If you use the Unitel T+ tourist eSIM, save its customer line, +238 910 0555, which the shop lists as open Monday to Sunday from 8:00 to 22:00, Cape Verde time.
• On a weak island, a phone that shows bars but loads nothing is common: switch airplane mode on and off before assuming the eSIM is broken.