April to June is usually the most popular time to visit Istanbul, especially if you’re focused on city breaks, culture, and historic stays. Outside that window, weather, crowds, and prices can change—so the neighborhood you pick matters more.
If your dates are fixed, choose between Sultanahmet and Karaköy / Galata first, then decide whether central hotels or a more spacious stay fits your days better.
If your dates are flexible, shifting a week or two around April to June can mean easier availability and a less crowded feel.
Beşiktaş / modern European side is useful when Sultanahmet feels too busy or when you want a different balance of price, quiet, and access.
Pack a little buffer into your arrival day in Istanbul so the first night is about settling in, not racing across town.