So you never end up NOT being able to visit a museum
I couldn't stress enough the importance of booking your tickets in advance, especially when it comes to the Uffizi Gallery, Accademia Gallery, Pitti Palace, the Medici Chapels and Bargello Museum. During peak season, the tickets are sometimes sold out for weeks ahead, so start planning early. Also, keep in mind that, when booking your tickets in advance, in some cases you will have to pay the booking fee of approximately 2-4 EUR pp.
Here's the website where you can find official tickets for all these places and more:
https://webshop.b-ticket.com/webshop/webticket/eventlist
Do not fall for tourists traps - there will be numerous unofficial websites trying to sell you tickets, too (including last-minute access). They could be legit, but you will be overpaying (sometimes A LOT!) but they could also be scams. Always choose the official channels for safety!
There are of course some museums that you can visit for free at all times (no booking needed) that you can find among the "things to do" section of my guide. If the price is not stated, then the place is free to visit!
There are some good ways to save many when visiting Florence and to make your trip as budget-friendly as possible if you plan wisely - and I am happily sharing all the best free and budget places that do not require any prior booking in this guide.
Go check out my guide for the best free things to do as well as itineraries and travel tips to make your trip unforgettable.