Paris for a day is doable
 

I often see people saying you need lots of days to visit Paris or any big city in Europe. I spend not even a full day and yet I got a good taste of Paris.
I think if museums are concerned PAris can be done in 3-4 nights at most even.

I did a one day trip from Amsterdam (flew with Transavia in the morning) and saw all these for a few hours:

- the Notre Damme (from outside)
- the Arc de triomphe
- walked along the Champs elysees (sp)
- walked around/next to the Eiffel Tower
- Passed by the Moulin Rouge on my way to the Garre / train station (I don't rememebr which one as it's not far from two train stations).

I returned to Eindhoven in the Netherlands for dinner by train. I even had to get off in Brussels because I foolishly have booked a ticket for two days later and still had time to go back to the Netherlands for dinner.
I even brought a box of macarons on my way to the train station in Paris as a souvenir.
So, yes, it seems Paris can be done in a day trip, sure no restaurants or going into cathedrals or museums. And I skipped the Louvre and Versailles of course. If you add them, I can see how more time is needed. But it's perfectly doable as a day trip. On the other hand Vienna and London seem somehow more spread out to be able to see so many things so fast.

If it's Tuesday it must be Belgium.

from the OP's description I think he missed visiting Paris

And I think some posters here are “of an age” and forget what it’s like to be a first-timer who has dreamt of Europe.
I was with a friend in Paris for five days. She knew I had been to London and asked if there was anyway I’d be willing to go there for one day. Well, yes!
We bought Eurostar tickets and were off for a wonderful day visit.
No, of course we didn’t see everything but we were in London!

If one just wants to go to Paris to say they have been to Paris, sure. But if they actually want to see more than two landmarks, probably not. And would require to be in close proximity to another viable city (London, I guess).

What is it with the fly bys of major cities lately? Is it social media? AI? That is fueling all of this?

I fail to see what the problem is and why all the negativity about seeing a place for just 1 or 2 days. Of course someone won’t see everything and depends on what one thinks is everything.

I live close to 2 major US cities and the US capital and haven’t seen everything. Why can’t people just be happy for others who want to share what they did with their limited time? It’s not new as suggested itineraries do start at 1 day. Lots of people can just for 1 day. I would love to have a day in Paris.

Yes, you can breathe the air in Paris and see a famous landmark with a bit more detail than in an on line video, but is that actually a visit? This shows the difference between "can" and "should."

To-MAE-to, To-MAH-to. And I fail to see the problem to let people know that sometimes their plans might be unrealistic. And Washington DC is not Paris....YMMV.

It makes perfectly sense to stay only 1 day in a big city, if you are interested in just a few monuments or only 1 or 2 museums and nothing else. But only if youare well prepared for that or can do it with a excellent local guide.
For example:
old coptic churches in Cairo
railway stations of Paris
Byzantine mosaics in Istanbul
Museo delle Scienze e Techniche Leonardo da Vinci a Milano
but all that has absolutely nothing to do with a "visit of a town"

Not to mention the benefit of cheaper airfare to Europe from the East Coast. And, as someone who has been to NYC, would NEVER suggest someone go there for a day trip. However, sure, if you live within a few hour train ride, it is plausible, I guess. I also live near two major metro areas and a major touristic area. And I also know the logistics to travel in the area. And I have seen insane itineraries from people who think they can see all of San Francisco , go to Yosemite the next day and see Lake Tahoe the same day as Yosemite. Not realistic.

The advantage of living in Europe: an efficient public transit system and interesting places.
I can take on an overnight ferry ifrom Gdynia, spend a full day in Karlskrona, and take the overnight ferry back for 369 Canadian pesos.
I can even bring my bike.

It's a pity they didn't take the train, which would have been cleaner, was probably quicker but probably cost more sadly. What does it matter if they wanted a day trip to Paris? I have seen other posters wanting to do a day trip from Paris to Amsterdam and they received plenty of advice on how to do it.
Not everyone wants to visit churches and museums.

My sister-in-law did a day trip to Paris from Buckinghamshire by train, and had a fabulous day out.

Disagreeing is not being negative...

When DH and I lived in Paris in the eighties we’d take frequent weekend trips to London and the Benelux countries. Drive out Friday afternoon and return Sunday evening. We’d have just the whole of Saturday and Sunday morning, but we went often enough and always had something specific we wanted to see/do, so it worked well for us.

I’ve read other posts from tanek so am interested in the information they present. That was the reason I even read this. I would hate for someone not to share their experience as Paris is one of my favorite places. Any time spent there is worth it to me which I enjoy hearing about. I just might learn something I didn’t already know.

I too once visited Paris for the day from London. I was taken by a client on a corporate entertainment day out. Eurostar out and back. Breakfast on the train out and champagne on the train back. We were ferried around Paris in a limo bus to see a few of the key sites Champs Elysee, Monmartre, Eiffel Tower etc. Lunch in a "traditional bistro" . We all really enjoyed the day for the experience. Whether it was Paris or the champagne, I'm not sure!. Did I get to see all of Paris? Of course not but who cares?

We have deleted four posts and edited two others for being unnecessarily argumentative. People can have different travel styles. Let's keep things civil.

If I lived in Amsterdam I would take a day trip to Paris for lunch. I’m envious 🤣

During our five+ years in Brussels and four years in Maidenhead, England, I did more than 70 day trips to Paris, either solo or with my husband. From Brussels it was especially easy, we could get from the door of our apartment to the base of the Eiffel Tower in about two hours. Of course, we always had a pet sitter lined up to keep Raisin, our English cocker, company while gone all day. From Maidenhead, the trip was faster when Eurostar trains were served at Waterloo station. Took a little longer when Eurostar moved to St. Pancras.

Sometimes I had something specific to see/do on my list, sometimes it was just for wandering around. As a general rule, my/our energy would flag late in the afternoon. That was when I usually took a tea break at a cafe with comfortable chairs -- sometimes a luxury hotel lobby or, more often, the Cafe de l'Esplanade (serves Damman Freres tea, my fav French tea brand): https://cafe-de-lesplanade.fr/ For the day trips from London, I normally bought a reduced price first class ticket, which included a light breakfast on the way to Paris and a light dinner on the way back.

If you happen to live in a European city well connected, a quick math will show that you can "do" all cities within a 2-hour flight time. Morning flight at 7ish, return around 8 gives you at least 7 to 8 hours to spend at destination. Would it be Paris, London or Vienna, you can obviously see a lot, even visit a museum, have a proper lunch...
I did a lot of these day trips when I was younger, leisure or business. But no more. It is a very long day, you need to keep an eye on the watch not to miss the flight.. and I am much more concerned by environment issues.