Florence Duomo sandals?

I don't think it's just a translation issue. We climbed the many flights of uneven stone stairs to the dome, and were happy to not worry about stubbing our toes. I understand your wish to only bring one pair of shoes. One idea is to ask someone in charge the day before if your walking sandals will pass muster. If they won't, and the Duomo climb is a must-do, you can buy a lovely pair of Italian leather shoes. Please report back on how this goes.

Where did you read that?
It just says to wear comfortable shoes and not heels in the link I read: https://www.duomomilano.it/en/regulations/regulation/

Oops--sorry I misread--disregard!

What about something like these:
https://fitkicks.com/
I wear Xero shoes, too and also am a good hiker. These don't offer any support, but you could also use them in the hotel rooms (I usually pack a pair of flip flops for that and bathrooms/showers) and they weigh next to nothing.
It's been more than 20 years since I climbed the Duomo. I don't remember the rules then! I hope this helps!

I was lucky on the Cinque Terra trail (they also specify no sandals) because my Keen sandals have a toe cover on them otherwise it would have been a no go at the check point. I guess you need to decide if seeing the Duomo is worth taking a closed toe shoe with you or not. You could also buy a cheap pair of Keds and donate them after.

I just checked the descriptions of duomo tours offered by 3 different companies that are frequently recommended on the Italy forums (Walks of Italy; Context; The Tour Guy) and while all mention the need to cover shoulders and knees, none of them include a footwear mandate.

If I was to guess, they are trying to dissuade people from attempting the dome climb in flipflops or flimsy, smooth-bottomed fashion sandals. Bad idea, that. That aside, because sandals are rather popular with the Brothers (monks) and Sisters (nuns), I can't imagine they'd throw the Good Book attcha for exposing heels and toes. :O)

https://www.shutterstock.com/image-photo/florence-italy-09152017four-old-nuns-white-1054470113

Where did you read that?
It just says to wear comfortable shoes and not heels in the link I read: https://www.duomomilano.it/en/regulations/regulation/

That link is for Milan, the OP is going to Florence.

I found the sandal info here, on the main page under the section about the Baptistery. It does not say anything at all about footwear for the Duomo climb, and we are not planning to climb the Duomo.
(we are devout Catholics, and dressing modestly and appropriately while in a church is an absolute given - my kids will not be wearing shorts, we'll all be in dresses/ skirts, etc. I'm having a hard time understanding the quibble over sandals, though, and I can imagine that flip flops in church are definitely not respectful.... no problem there.... but, sandals? As someone else mentioned, yeah, the good Brothers and Sisters often wear Birkenstocks and other sandals!!)

https://duomo.firenze.it/en/725/giotto-pass
Baptistery
• Access from the North Door (Martelli's street side).
• Appropriate clothing is required for a place of worship: access is not permitted with bare legs and shoulders, wearing sandals or hats.
• The recommended duration for the visit is approx. 30-45 minutes.

Honestly, I wouldn't worry about it at all. Do a google on the subject and you'll find that same answer to umpty other visitors having had the same question.

Interesting that the Giotto pass page you linked states the sandal ban when visiting the baptistry when the dedicated page for the baptistry doesn't mention it at all yet it's there on the page for the cathedral. It's also not mentioned on the page for Santa Reparata either even though one can also visit the main body of the duomo from that part. Italian websites can be, well, interesting...

https://duomo.firenze.it/en/discover/baptistry
https://duomo.firenze.it/en/discover/cathedral
https://duomo.firenze.it/en/discover/crypt-of-santa-reparata

Really, don't worry.

This is what I come up with when I google the question:

“No, sandals are generally not allowed inside the Florence Duomo (Cattedrale di Santa Maria del Fiore). The dress code for the Duomo requires visitors to dress respectfully, which includes covering shoulders and knees, and specifically prohibits sandals.
More details:
Official Website:
The official website of the Duomo states that sandals are prohibited.”

We’ve been in many churches in Europe and Italy seems to be the most strict with their rules but who knows they might single you out, they may not.

The Baptistery restriction might be more because of the restoration works than for any modesty requirement.

Thanks, everyone.
Well, looks like I'll have to throw another pair of shoes in my bag in case I get stopped. Better safe than sorry. I will be sure to report back what happens when we get back, I'm sure others will be curious..... I am interested to know if it's due to safety or due to modesty. Inquiring minds want to know!!!

Just a start:
https://community.ricksteves.com/travel-forum/italy/no-sandals
https://www.facebook.com/groups/tuscanytraveltips/posts/1860520687799506/
https://community.ricksteves.com/travel-forum/italy/question-about-proper-attire-in-n-churches-in-italy

Walks of Italy's "Alone in the Duomo: VIP After-Hours Tour with Dome Climb & Private Terrace Access" tour says this:

"Shoes with heels and flip-flops are prohibited inside the Cathedral."

....but they don't include that info on some others of their duomo tours I looked at. I'm betting that it's spiky heels they don't want; could damage the floors or be a danger on the steps but just guessing.

But short story long, I've yet to read a review from someone turned away because of their footwear - and I've scrolled through a TON of reviews - although the same isn't true for some wearing knee-baring shorts/skirts or strap-y sundresses, and even the covered-knees-and-shoulders rule isn't consistently applied depending on the guards on any given day. Regardless, we followed that particular rule religiously for all Italian churches; pun absolutely intended. But If you are still worried, then pack another pair of shoes; maybe a dainty little pair of fold-over, space-saving flats JUST for the church and padding around at the hotel? Maybe these?

https://www.amazon.com/Silky-Toes-Womens-Foldable-Travel/dp/B0BJQSLPYP/ref=asc_df_B0BJQSLPYP?mcid=0b2666e7c8fa389982d3ea7246289273&hvocijid=14308499878306914060-B0BJQSLPYP-&hvexpln=73&tag=hyprod-20&linkCode=df0&hvadid=721245378154&hvpos=&hvnetw=g&hvrand=14308499878306914060&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019610&hvtargid=pla-2281435178338&psc=1

I’ve been into the Duomo in Florence many times and this is the first I’ve ever heard of “no sandals”.
I’m thinking it would apply to people climbing the Dome, for safety reasons.
But just to go into the building?
I’m thinking no one is looking at feet.