Internet in Vietnam: Ha Giang, Sapa and Ha Long

Vietnam has better coverage than most people expect — fast 4G in cities, along the whole coast and even in small Mekong Delta towns — and then loses it completely in exactly the places you came for: the Ha Giang passes, the rice valleys around Sapa, the islets of Ha Long Bay. This guide is about where it works, where it does not, and how to plan around that.

How to get online in Vietnam

Roaming with your own carrier

Vietnam sits in the most expensive zone of almost every tariff: daily passes with a few hundred megabytes, or pay per megabyte. For a three-week trip around the country it is easily the worst option. Check your tariff, but expect to rule it out.

A local SIM from Viettel, Vinaphone or Mobifone

Sold at Hanoi, Da Nang and Ho Chi Minh airports, in official shops and in many small stores, with your passport. They are among the cheapest in the world per gigabyte. The downsides: queueing after a flight, taking out your own SIM, and the fact that stalls at the airport exit sometimes sell you a different package from the one advertised. If you are staying for months, it pays off.

Travel eSIM

You buy the days of the trip, install the QR at home on wifi and land connected as a roaming visitor. Your home line stays in the phone with its data off, for bank texts and calls. It is the easiest option for a one-to-four-week trip, and it skips the paperwork exactly when you least want to deal with it.

Real coverage: who covers what, and where it drops

Three networks: Viettel, the largest and the one that reaches furthest into mountains and countryside; Vinaphone and Mobifone, solid in cities and along the coast. Travel eSIMs run on one of them, sometimes on several.

Vietnamese coverage is genuinely impressive: fast 4G in the cities, along the entire coast, on the main roads and even in small Mekong Delta towns. Well covered: Hanoi, Ho Chi Minh City, Da Nang, Hoi An, Hue, Ninh Binh, Nha Trang, Da Lat, Phu Quoc and Can Tho.

Where it weakens, whichever carrier you are on:

• The Ha Giang loop: fine in Dong Van, Meo Vac and on the main road; nothing on several passes and side turnings.
• Sapa and the rice valleys: coverage in town and at the larger homestays, patchy on the routes between villages.
• Ha Long and Bai Tu Long bays: signal near the coast, little or none among the islets.
• Phong Nha caves: in the village yes, inside the caves and on jungle trails no.
• Mekong canals and the small ferries: lost as soon as you turn into the narrow branches.
• National parks (Cat Tien, Ba Be): at the entrance and the lodges yes, on the trails it depends.

As always, plainly: the eSIM uses Viettel’s network or whoever covers you, not one of its own. Where there is no mast, no eSIM works, ours or anyone else’s. In Ha Giang and Sapa: offline maps and tell someone your route.

How much data you need

Type of trip	Typical use	Plan that fits
Cities and coast: maps, Grab, messaging	400-600 MB a day	5 GB for a week
The above plus social posting daily	800 MB - 1.2 GB a day	10-15 GB for three weeks
Daily video or working from the phone	Over 1.5 GB a day	Unlimited by days

The breakdown app by app is in how much data do I need for a trip.

Installing the eSIM and landing connected

1. Compatibility: dial *#06# and look for the EID; the phone must be carrier-unlocked. List by brand on compatibility.
2. Buy for the days of the trip: validity starts with the first connection in Vietnam.
3. Install at home on wifi.
4. Lines: your home line for calls and texts with its data off; the eSIM as mobile data with roaming on.
5. On landing: turn off airplane mode and wait to see “Viettel”, “Vinaphone” or “Mobifone”. Book your Grab from inside the terminal.

Every menu, step by step, in how to install an eSIM.

Apps people use in Vietnam

• Grab: cars, motorbikes and food, at a fixed price. The motorbike is extremely cheap and it is how people get around Hanoi and Ho Chi Minh City. Alternatives: Be and Xanh SM, the electric taxis.
• Zalo: the national messenger. Many hotels, drivers and agencies reply there before WhatsApp. Install it before you leave.
• Google Maps with the cities and mountain areas downloaded. On the Ha Giang loop it is essential.
• Google Translate with Vietnamese downloaded: the camera translates menus, which outside tourist areas are in Vietnamese only.
• 12Go and Baolau for buses, trains and ferries; trains can also be bought on the Vietnam Railways site.
• Payments: locals pay by QR from their bank; you will use a card in larger places and cash at stalls, markets and on buses. ATMs have low withdrawal limits and a fee: take out more at once, and check the large notes, which are hard to break.

Connectivity tips for Vietnam

• Before boarding a night bus or train, download the map, the ticket and something to watch: onboard wifi, where it exists, is token.
• Motorbiking in Ha Giang: offline maps, shared route and a power bank. On several passes nobody has signal.
• Message your homestay on Zalo or WhatsApp with your arrival time before leaving an area with coverage.
• Wifi is everywhere and it is good: use it to download and for long video calls, and save your data for the street.
• Calls home: over an app, always.
• If you continue to Cambodia, Laos or Thailand, the local plan stops at the border: look at a regional Asia plan.

Rough price

The block at the top shows what a Vietnam eSIM costs in the MovaSim catalogue today, with the unlimited-by-days option and the cheapest by gigabytes; the Vietnam page has every plan and which countries each one covers. And if you do end up buying a Viettel SIM in Hanoi, the coverage and app advice here works just the same.