Lucca or Bologna?

The answer, in part, depends on what you like to do and on what you are doing the rest of your trip? Also, is this a first time to Italy (or first time to these places)?

Two very different experiences - Bologna is almost 10 times the size of Lucca in terms of population. Lucca is compact so you can see much of it during a day trip.

Bologna may offer more of a contrast in cuisine compared to what you'd be experiencing in Florence.

I second the opinion that it depends entirely on what sounds like a great day to you. Are you city people or town people?
- A bustling university town going about its foodie centric life with buses and cars in the few ancient city streets that will support traffic with medieval towers dominating the downtown center.
- A quieter, small mostly pedestrian village-like experience with churches, stores and scattered piazzas surrounded by the walls now turned into a running park.

You will be spoiled for restaurant choices in either place but you could see much of Lucca in a day where a trip to Bologna would probably be get a small taste and decide whether you would want to go back. If your kids were younger I would definitely say Lucca but the 22 year old may resonate more with the college energy of Bologna south of the city center.

I think the distinction between them is pretty clear. Hope that helps, have a great trip,
=Tod

Small city vs large city (although not really 10 times the population, maybe 4 or 5 times), both flat, both with plenty to keep you busy for a day. Bologna is farther but faster to reach thanks to the bullet trains, that Lucca doesn’t have. Your choice really.

Bologna isn’t a day trip from Florence unless you know what to see and do. If you’re going to wander stick with Lucca. The best way to experience Bologna is to spend a minimum of two nights if not more.
If you go to Lucca, make sure you take a direct train (1h 30m) there and back. You will depart from Florence’s (Firenze) S.M. Novella station: https://www.trenitalia.com/en.html.

Been to both and I would recommend Lucca.

30 minutes high speed train from Florence to Bologna so that gives you a full day. Bologna is one of my favorite cities in Italy. Lucca is nice for the walk around the wall and its historic center. Its a win either way in my opinion.

I've been to Bologna as well as Lucca and enjoyed them both but Lucca has my heart. I think in this case, as you are coming from a city (Florence) that Lucca might provide a nice relaxing contrast for a day-trip. Although there are no major sites (there are smaller ones, like climbing the Guinigi Tower - tower with trees on the top) it is just WONDERFUL to walk around and simply EXIST in Lucca.

You can also rent bikes reasonably and ride around the walls which is really quite lovely. As you make your way around you will run into a sweet outdoor/indoor cafe to stop for a cappuccino, cool drink and snack. Just sit back and watch the world go by. There are lovely shops, beautiful churches, pretty antique cafes and bakeries in town. Lucca is an easy walk from the train station (10 minutes) and the ground is flat. Here is a fun video (make sure you have your volume up) that will give you a flavor of how you'll feel in Lucca (at least this is how I felt): https://www.youtube.com/watch?v=qHYvkkrSLKA
I've been home a little over a week now (18 days in Italy) and am going through a bit of withdrawal -- I'm really missing it all but maybe especially Lucca.

Let us know where you end up!

Lucca. Smaller..cool walled city..walk the rampart..or easily rent bikes..enjoy small cafes..and a lovely lunch..and the dire t train to Florence! Have fun!