What a reserved ticket does and does not get you past
Skipping the queue at the Doge's Palace
There is more than one queue in St Mark's Square and a Doge's Palace ticket only deals with one of them. This explains which, how much time it really saves, and what still holds you up.
Book your Doge's Palace entry ↗The queue your ticket removes
The ticket-office queue. In high season this forms along the waterfront side of the palace and regularly runs to an hour or more in the middle of the day. A reserved dated ticket lets you go to the pre-booked entrance instead and skip it entirely. That is a real and substantial saving, and it is the main practical reason to book ahead.
The queue it does not remove
Security. Everyone entering passes through a bag check, and at peak times there is a short line for it regardless of what ticket you hold. It is normally a few minutes rather than an hour, but it exists, and no ticket sold by anyone bypasses it.
The bottleneck inside
The one nobody warns you about. The route narrows sharply at the Bridge of Sighs and the prison corridors, and in the middle of a summer day the flow through that section slows to a crawl. Booking a ticket does not help with this at all. Going early or late does.
A different queue entirely
St Mark's Basilica, next door, has its own separate queue and its own separate ticket, and it is often the longest line in the square. Many visitors assume a palace ticket covers it. It does not, and the two are not connected in any way.
How much time you actually save
In February on a weekday morning, very little — you could probably walk up and buy a ticket in ten minutes. In July at midday, easily an hour, sometimes more. The value of booking ahead scales almost entirely with season and hour, which is worth knowing when deciding whether it matters for your particular date.
The trade-off
Reserved tickets are dated and, on this listing, non-refundable. So you are exchanging flexibility for queue time. In high season that is an obviously good trade. On a quiet winter weekday it is a much closer call, and if your plans are genuinely unsettled it may not be worth making.
Arriving
Get there about ten to fifteen minutes before your slot. Much earlier and you will simply wait; much later and, on a busy day, you may find yourself folded into the general flow. Large bags have to go in the cloakroom, so allow for that if you are carrying one.