The groups, and how they actually differ
The Cyclades are the Greece of the postcards: white villages, bare rock, deep blue water, and the densest ferry network in the country, which is why almost every island-hopping route runs through them. They are also the windiest. The meltemi blows hardest here in high summer, and it is the single thing most likely to rearrange your plans. Start with Santorini, Naxos, Paros, Mykonos or Milos.
The Dodecanese, off the Turkish coast, hold the layered history: a walled medieval city on Rhodes, an ancient healing sanctuary on Kos. They are further from Athens, so people usually fly in and stay, rather than hop.
The Ionian islands, on the western side, are the green ones, and they are essentially free of the meltemi. That is the trade at the heart of them: calmer water and lush hills, in exchange for more rain and a very different, more Italian-feeling architecture. Corfu, Kefalonia and Zakynthos lead them.
Crete is not really an island in the hopping sense. It is a country-sized place with its own mountains, its own food and its own four-hour drives, and it deserves a trip rather than a stop. See Crete.
How to choose, in one move
Do not start from a list of islands. Start from the trip. If you are travelling with children, the test is a sandy, shallow beach and a short transfer, which rules out the famous cliffs: see Greece with kids. If it is a honeymoon, pair an icon with somewhere quiet: see the honeymoon guide. If it is the nightlife you want, the islands split sharply by scene: see the party islands.
Then check the calendar, because the season decides what is even possible. Ferries run on tiers, small islands close out of season, and the sea is warmest well after the air is: when to go and how the ferries work are the two pages that turn a shortlist into a route.
Then sequence it, do not just pick it
Two islands in a week is a holiday; four is a series of ferry terminals. Once you know which islands, the island-hopping guide covers how to order them so every boat moves you forward, and our itineraries give you routes with the legs already sequenced.