The short verdict
For Vietnam, Viettel is the carrier to prioritize. It is the largest Vietnamese carrier (state-owned by the military), has the widest coverage including rural provinces, mountain areas, and the islands of Phu Quoc and Con Dao, and has the fastest 5G rollout. Mobifone is a strong second in cities. Vinaphone is competitive but has less rural coverage. Flysimio offers Viettel-routed Vietnam eSIMs at the best price we found. Vietnam's eSIM market has improved significantly — most providers now offer reliable plans.
Vietnam eSIM comparison table (2026)
| Provider | Plan | Price | Network | Refund |
|---|---|---|---|---|
| Flysimio | 5 GB / 30 days | $5.75 | Viettel | 14-day full |
| Airalo (Vietnam eSIM) | 5 GB / 30 days | $9.50 | Mobifone | Unused only |
| Holafly | Unlimited / 7 days | $13.00 | Viettel | 24-hr unused |
| Nomad | 5 GB / 30 days | $8.00 | Viettel | Unused credit |
| Saily | 5 GB / 30 days | $8.99 | Mobifone | Case by case |
Coverage across Vietnam
| Destination | Coverage | Notes |
|---|---|---|
| Hanoi | 5G on Viettel and Mobifone | Full coverage; Old Quarter and Hoan Kiem area excellent |
| Ho Chi Minh City | 5G on all carriers | District 1 and tourist areas fully covered |
| Hoi An and Da Nang | 4G on Viettel and Mobifone | Strong coverage throughout; beach areas covered |
| Ha Long Bay (cruise) | 4G on Viettel near shore | Coverage on the bay itself; stronger near Cat Ba Island |
| Hue | 4G on Viettel | City centre and Imperial City well covered |
| Phu Quoc Island | 4G on Viettel | North and south Phu Quoc covered; interior jungle patchy |
| Sapa and the north mountains | 4G on Viettel in town | Viettel covers Sapa town; trekking routes in valleys have signal; rice terrace ridges patchy |
| Mekong Delta | 4G on Viettel | Major towns covered; remote waterways and small islands variable |
Which Vietnam eSIM for your trip?
| Trip type | Recommended | Why |
|---|---|---|
| Hanoi + Ha Long Bay | Flysimio 5 GB (Viettel) | Viettel covers both destinations |
| Ho Chi Minh City + Mekong Delta | Flysimio 5 GB (Viettel) | Viettel has best Mekong rural coverage |
| Central Vietnam (Da Nang, Hoi An, Hue) | Flysimio 5 GB (Viettel) | Full coverage of central coast |
| Phu Quoc beach holiday | Flysimio 5 GB (Viettel) | Viettel covers the island's main tourist areas |
| North Vietnam trekking (Sapa, Ha Giang) | Flysimio 10 GB (Viettel) | Viettel reaches mountain towns; signal limited on remote passes |
| Full country north to south | Flysimio 10 GB (Viettel) | One Viettel plan covers the entire country |
Installing your Vietnam eSIM
- Buy before your flight — install on home Wi-Fi.
- Open the Flysimio email for the QR code.
- iPhone: Settings → Cellular → Add eSIM → Use QR Code.
- Android: Settings → Network & Internet → SIMs → Add SIM.
- Scan the QR code.
- Label it "Vietnam" and set as data line.
- Disable Data Roaming on your home SIM.
- Your phone connects to Viettel when you land at Hanoi (HAN), Ho Chi Minh City (SGN), or Da Nang (DAD).
Frequently asked questions
What is the best eSIM for Vietnam?
Flysimio on the Viettel network is the best Vietnam eSIM for most travelers. Viettel has the widest coverage in Vietnam including rural mountains, islands, and the Mekong Delta, and Flysimio offers the lowest price.
Does eSIM work in Ha Long Bay?
Yes, on Viettel. Ha Long Bay has 4G coverage near shore and around Cat Ba Island. On overnight cruise routes in the middle of the bay, signal is present but weaker. Most cruise ships also have Wi-Fi, which is useful when signal drops.
Does eSIM work in Hoi An?
Yes. Hoi An Ancient Town and the beach area (An Bang, Cua Dai) are fully covered by Viettel 4G. The cycling routes between Hoi An and Da Nang are also well covered.
Which eSIM uses Viettel in Vietnam?
Flysimio, Holafly, and Nomad route through Viettel for Vietnam plans. Airalo and Saily use Mobifone. Viettel has the widest geographic coverage and is the recommended carrier for any travel outside major cities.
How much data do I need for Vietnam?
Vietnam has very fast and cheap mobile data. For a two-week trip with moderate use (maps, social, messaging), 5 GB is sufficient. Vietnam's fast network means you consume data quickly, so heavy users should consider 10 GB.
Does eSIM work in Sapa?
Yes, on Viettel. Sapa town has 4G LTE. Trekking routes in the Muong Hoa Valley and to Ta Van village have signal on the main paths. Remote mountain passes and ridge lines above the valley have reduced or no signal.