I understand the confusion so I've already tried to provide a more complete answer here:
https://www.visitflorence.com/what-to-see-in-florence/booking-florence-museums.html
Make sure to read that because I offer more "cases" in which it makes sense to book, when to book, and when to get the museum pass.
It essentially comes down to this:
1. tickets bought online ALL make you skip the general ticket line, but there is also a line to get in at each time slot for those who "PREBOOK" their tickets. Yes, because you don't actually get tickets, you have prebooked them and you still have to stop and pick up actual paper tickets once there. This is true for all museums here in Florence.
2. all tickets, no matter where you buy them from, include a fee for booking them
3. buy online from the "official" museum website to get you the
cheapest ticket
BUT also consider that the official website does
NOT offer ticket
ANY CHANGES OR CANCELLATIONS at all, none whatsoever! Other vendors online do include changes or cancellations as an added service yet they do offer tickets that cost more upfront, essentially to cover part of the cost of any changes or cancellations they do. So you might want to consider paying more upfront if you want that possibility, as some know their plans might change. You can avoid that by holding off and not buying museum tickets until closer to your date, of course, once plans are more solid.
4.
TOURS - I highly recommend them as a high value added for your visit, because you definitely see the works and learn about them in a way that makes the entire experience more valuable. They include the cost of tickets, so I think it is one of the best ways to visit museums.
Museums here in Florence do not generally offer any tours directly, so all tours have to be through outside agencies and licensed guides.
These are
tours in Florence, that's our affiliate link to Viator. Consider looking into walking tours that include museum visits, or just tours dedicated to the two most visited museums, the Uffizi and Accademia.
** If you miss your entry time, you have to buy a new ticket. You have 20 minutes leeway to get in, no more. So don't miss your entry time! **
So these are your choices -- I highly recommend getting tickets for the Uffizi and Accademia between April and October, when lines are long.... the pre-booked lines are not short, but they are shorter so it avoids wasting too much time in line. Tours are my own personal preference, as they skip the link too with the prebooked tickets.
Finally, consider that the Firenze Card
used to allow visits to the Uffizi and Accademia WHENEVER you wanted while the card is valid without the need to book ahead, they NO LONGER do that. You now still need to book a time for your visit to the museum. In that case, it makes sense to just buy tickets for those two museums separately, choosing a date and time... at that point, the card is no longer a great deal at all. Most other museums on the card can be visited without needing advance tickets so you can buy on the spot.
Last - you don't need to book tickets, there is always the possibility to get in the general ticket line and wait to go in. The Uffizi has the longest lines here but the Accademia ones are no joke either, that's why those are the two I do recommend getting tickets for. Look at it this way: you can pay more for those tickets, save on all the prebooking fees at other museums where you just buy tickets the day of your visit.