Intro: I strongly encourage anyone in or coming to Florence to try to book this tour package, which also includes entry (within 3 days) to the Baptistery, the Opera del Duomo Museo and the crypt of Santa Reparata.
That said, there are other options (link at the end of this post) but I also strongly advise that you book in advance!
•♦•
♦ Up! Up! Up!
While the restoration of the Baptistery of Saint John the Baptist continues, there are limited weekly guided tours (in English & Italian).

Once again I climbed the scaffolding today (the first time was almost 2 years ago)…
Hard hats on, our guide led us up the 75 stairs.
No photos are allowed during the tour itself, but it is an incredible experience to be able to get so close to the exquisite mosaics!

Yes, it’s ALL mosaics – the detail and craftsmanship (most estimated at least 800 years old ) is simply beyond description.
•♦•
♦ Museo del’Opera del Duomo
The Museo del’ Opera del’Duomo is absolutely phenomenal! Part of the “package’ (and there are several to choose from) when I booked my guided Baptistery tour you have 72 hours to visit this treasure trove of masterpieces.

As a reminder, “opera” in Italian and in this context means “works”, it is a museum that contains the works of a historical site, often a basilica or cathedral.
I visited (for the umpteenth time!) on Sunday and it was virtually empty! Lines snake around the Duomo itself (which is free but can take HOURS – no reservations allowed)…but this marvelous museum is often overlooked or not on the itinerary of visitors – and that is truly a huge loss…

Although the museum has been reconfigured, it has always been a favorite of mine here in Florence. Consider that MANY of the original masterworks created for the Cathedral facade/interior, Baptistery, and the Campanile (bell tower) are displayed here…plus so much more!!

Original masterpieces by Michelangelo, Donatello, Della Robbia, Brunelleschi, Ghiberti, Verrocchio, Arnolfo, Pisano and so many many more are exquisitely exhibited.

The museum is thoughtfully curated with excellent multi-media and other very informative features (in Italian and English).

Although, I love sharing with you but photos can only hint at the sheer scale and beauty of this collection.

Conveniently located near the Duomo, I highly recommend that you visit. I always spend at least two hours here but if your time is limited, (and there are no lines!), I highly recommend and promise that not only will your time will be well-spent, but you will be sooo glad that you did. (FYI: You can make reservations although it is rarely crowded.)

I have written about this museum before… and it is definitely a favorite and it never ceases to deepen my profound appreciation for all that they do to preserve the rich legacy of these monumental and iconic treasures.

♦ What You Should Know:
This monumental complex has several reservation/booking packages and options. They also offer audio guides in different languages.
To clarify: This particular tour which includes climbing the scaffolding f the Baptistery is very limited. However other packages are available daily.
Open daily from 8:30am to 7:00pm
♦ Review carefully:
• There are Three Tickets/Packages: Brunelleschi, Giotto and Ghiberti
• For GUIDED Tours: including the Baptistery, the Dome, the Balcony of the Dome and the Frescoes of the Dome
• The official website (in English):
https://tickets.duomo.firenze.it/en/store#/en/
⇒Please read the information carefully especially if you are considering climbing the balcony or dome. Also note there is a dress code for the Duomo!⇐