Sweden → Guernsey
Sweden plugs
Type C
Type FGuernsey plugs
Type GNo shared plug types. A travel adapter is required.
Compatibility: Adapter Required
Voltage — Sweden 230V — Guernsey 230V
Voltage is the same. Your devices should work normally.
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.