Yes — the tap water in Tenerife is safe to drink. This question comes up before almost every stay, so it is worth answering plainly before getting to the nuance, which is that safe and pleasant are not the same thing.
Safe, but mineral
Mains water here is treated and meets Spanish and EU drinking-water standards. Nobody is going to get ill from it, and you should cook with it, make coffee with it and brush your teeth with it without a second thought.
What visitors notice is the taste. A lot of the island’s water originates in galerías — tunnels bored horizontally into the volcanic rock to reach groundwater — and water that has sat in basalt carries the minerals to prove it. In the north it can taste flat or faintly chalky compared with soft northern-European tap water.
What people actually do
Most households here keep both. Tap water for cooking and washing; filtered or bottled water for drinking cold.
Five-litre bottles are the standard supermarket unit, they cost very little, and every shop from the small supermarket at the beach up to the Lidl on the highway sells them. A jug filter works just as well if you would rather not carry plastic up the stairs.
Our recommendation
We keep bottled water in the apartment for drinking and use the tap for everything else. That is not a warning — it is just what tastes better, and it is what your neighbours are doing.
Where the island’s water comes from
It is worth knowing, because it explains the taste. Tenerife has almost no surface water — no rivers to speak of — so most supply comes from galerías: horizontal tunnels driven hundreds or even thousands of metres into the volcanic rock to reach water held inside the mountain.
Some of those tunnels were dug by hand over decades. The water that emerges has been filtering through basalt for a very long time, which is exactly why it carries the mineral character you can taste, and why it varies noticeably from one municipality to the next.
Practical notes for your stay
The kettle will scale up faster than you are used to. That is normal and not a sign that anything needs reporting.
If you are here for a week or more, a five-litre bottle every couple of days is what most households get through. The small shop at the beach carries them, so you do not need the car for it.