These beaches don't qualify for the Blue Flag, not meeting its specific infrastructure rules. The nearest beaches that are tested are the West Shore and Conwy Morfa
In Wales the beach award scheme is administered by Keep Wales Tidy - see
here for a full map of beaches and which award they have gained.
The Marine Conservation Society has an important water testing role: see its Good Beach Guide for local results.
There is worthwhile beach along both sides of the Conwy estuary. This spot is next to Deganwy railway station. It has a small jetty, a nice, sheltered little crescent of sand, catches the afternoon sun particularly well and is a popular spot for messing around in boats. The cycle/coast path (aka Conwy Estuary Route - download Conwy CC pamphlet) can be followed downstream to the West Shore, or upstream to a new bridge over the railway and then to the RSPB reserve (which has a nice cafe).
DEGANWY: Exit A55 junction 18. Left, past Tesco and straight on at the big roundabout. At the railway station
turn left into Marine Crescent. If no space there then pay parking at the station or,
alternatively, there is a free parking area ¼mile up the main road.
CONWY MARINA: Exit junction 17 as for Conwy Morfa, turn left and then follow Meirionedd Drive to a mini-roundabout. Turn left and follow the road round right to the parking at its end.
Across the estuary from Deganwy is Conwy Marina. This beach has a car park tucked between the marina and the golf course and is worth knowing about as a sheltered spot in case of westerlies. Due to currents and boat activity no swimming or diving. This area is also referred to as Conwy Morfa; of historical interest parts of the WW2 "Mulberry" harbours were built in this vicinity.