The beaches in the resort are mostly fine pebbles. Split's beaches are very clean, the sea is bright turquoise thanks to the quartzite deposits at the bottom, and very clear (visibility up to 50 meters deep).
Which is the best beach in Split? No one can give you an unambiguous answer: there's a lot of choice and different preferences.
Bačvice beach
If you like sandy beaches, come to Bačvice in the city center: it's free to enter and has everything you need for relaxation, including nearby restaurants. You can also rent a jet ski here.
Trstenik Beach
A little further from the center is the fine-pebbled beach Trstenik. There is a footpath between it and Bačvice.
The beach at the Radisson Hotel
And even further away is the beach that belongs to the Radisson Hotel. It's also free, has cabins, sunbeds, and showers, and a café.