Both airports are outside the city and both depend on traffic. There are four ways to reach us; which is right depends on the hour and the number of suitcases.
A private transfer. The easiest, and the sensible one with luggage. You are met at the door, the price is fixed and there is no haggling. From Istanbul Airport 45 minutes to an hour and a half; from Sabiha Gökçen over an hour. Tell us in advance and we arrange it.
Metro (M11) then M2. The cheapest. M11 from Istanbul Airport to Gayrettepe, then M2 to Şişhane — a five-minute walk from us. About an hour and a half in total, and the change is awkward with cases. Sabiha Gökçen has the M4, with more changes.
The HAVAİST bus. It runs to Taksim; from there it is a fifteen-minute walk to us or a short taxi. Dearer than the metro, cheaper than a taxi. There is a luggage hold and you get a seat. In traffic the metro finishes sooner.
A taxi. Airport taxis are yellow or turquoise. Ask for the meter; if a fixed price is offered, decline. Booking through an app (BiTaksi, Uber) puts both the fare and the route on record.
If you land at night. The metro does not run through the night; the last services are a little after midnight. For a night arrival a transfer or a taxi is the only practical option. Tell us your arrival time — check-in runs to 23:00, and anything later we arrange beforehand.
One warning: Galata's streets are narrow and steep. Tell the driver "Şah Değirmeni Sokak" and ask to be taken to the door, or you will carry the cases uphill.