Vietnam → Spain
Vietnam plugs
Type A
Type C
Type FSpain plugs
Type CType FShared plug types: C, F
Compatibility: Compatible
Voltage — Vietnam 220V — Spain 230V
Voltage difference is small. Most electronics will work safely.
Device compatibility (phones)
Phones almost always support 100–240V, so yours should work safely. Check your charger label to confirm.
You likely only need a plug adapter (if socket shapes differ). Voltage is close between these countries.