Three national networks, two different races
Vietnam’s main networks are Viettel, Vinaphone (VNPT), and MobiFone, with Vietnamobile as a smaller fourth. They are not interchangeable labels on the same towers. A travel eSIM that prints VNPT is choosing Vinaphone’s grid. A local Viettel eSIM is choosing Viettel’s. The useful comparison is which race you care about: everyday speed in cities, 5G peak speed, or the chance of a cell on a highland road.
What Opensignal measured
The August 2026 Mobile Network Experience report collected data from 1 April through 29 June 2026. Everyday download speed was Viettel 56.7 Mbps, MobiFone 55.4, Vinaphone 54.6, and Vietnamobile 12.6. That is a tight race among the big three, not a blowout. 5G download was a different table: MobiFone 320.0 Mbps, Viettel 247.5, Vinaphone 339.2. 5G upload was MobiFone 31.9, Viettel 26.3, Vinaphone 29.4. Coverage experience, the 0–10 score Opensignal uses for places people actually travel, was Viettel 8.4, Vinaphone 5.5, MobiFone 4.3, Vietnamobile 1.4. 5G coverage experience was Viettel 1.1, Vinaphone 0.3, MobiFone 0.2. Consistent quality was Viettel 78.8% of tests, MobiFone 77.4%, Vinaphone 68.6%. Reliability points were Viettel 876, MobiFone 860, Vinaphone 833.
Read those together. Viettel was not the 5G speed leader in this report. Viettel was the coverage leader, including 5G coverage, by a wide margin on a still-low 5G scale. If a seller says “Viettel is the fastest 5G” without a date and a report, they are quoting a different year or a different methodology. We would rather show this table.
What nPerf measured
nPerf’s 2026 barometer covers April 2025 through March 2026. Vinaphone led the overall score at 74,587. Viettel was second at 71,703. Viettel’s download bitrate in that study was 76.48 Mb/s, up 49% on nPerf’s previous year. nPerf also gave Viettel the lead on overall latency and on web browsing, and said Viettel had led web browsing for four years running. Different companies, different tests, a similar story: the city-speed race is close and sometimes goes to Vinaphone, while Viettel’s practical reputation is reach and responsiveness.
What Ookla’s country index is not
The Speedtest Global Index, updated August 2026, lists Vietnam’s median mobile download at 360.77 Mbps, upload 59.84 Mbps, latency 20 ms. That median mixes subscribers of every operator who ran the Speedtest app. It is a country fact. It is not a Viettel fact, and it is not comparable line-by-line with Opensignal’s everyday download, which is a different method and a much lower number. We cite it so nobody pastes the 360 Mbps figure into a Viettel sentence by accident.
For a traveler the purchasing rule is dull. Buy Viettel if the map includes mountains, border highlands, or islands away from the resort strip, and accept that a 5G icon will be occasional. Buy a Vinaphone-based roaming eSIM only if you have checked that your days are urban and you prefer that brand’s app. MobiFone’s city scores in the Opensignal report are real. Its coverage-experience score is the lowest of the big three. This store sells the Viettel option, at $9.99, $14.99, and $18.99, 5GB high-speed per day.