6 days in Switzerland in August, flying into Zurich, flying out from Geneva. Suggested itineraries?

Is that 6 days or nights? Counting travel days? With six full days for sightseeing, if I was flying into Zurich and out of Geneva with kids that age, I'd go immediately to Luzern for 2 nights, Berner Oberland staying in Murren, Lauterbrunnen or Wengen for 3 nights and ending in Lausanne or Geneva depending on flight time. Travel by train.

Some might say spend all the time in Berner Oberland which would not be a bad choice, except I think that age person would enjoy some smallish Swiss cities, and Luzern is quite charming.

I think if you could add a day or two, that would really add to your trip.

If you're talking about this August you may have to make decisions based on where you can find lodging. The popular areas are going to be very slim pickins. Do not rent a car, the train system is wonderful. For 6 days (5 nights?) I'd probably just pick one base, two at most.

I would agree with the idea of picking one or two bases, but, I'm not sure it works given the short duration of the trip and the cities that the flights arrive/depart. I wouldn't want to spend any of the short vacation time in Zurich or Geneva.

I would suggest 3 nights in wengen or murran and 1 night in Lucern(on way out) and perhaps, one night in zermatt if u plan to take the glacier express? if not, two nights in Lucern should be fine

Hopefully that is 6 nights. That could mean 2 nights Luzern, 3 in the Berner Oberland, and one in a town on Lac Leman (Montreux, Lausanne, Vevey, Morges) for the night before flying out of Geneva. Just as suggested above by Jules.

If only 5 nights, take a night from Luzern, not the BO.

Lodging may indeed be limited, but I see that 2 apartments I know in Mürren have some availability in August. Either will sleep 5 adults comfortably in 3 bedrooms.

One is “Sportzentrum 2.30” located above the Sports Center complex. Rent from this agency:

https://www.topapartments.ch/en/6-persons

The other is in the same building, actually adjacent to the “Sportzcentrum 3.42” apartment on that page. It is available on Air BnB under the name “a Little Bit of Paradise”. I cannot post a link because my iPad defaults to the app for Air BnB. But you can Google it. We rented this apartment last September, with our son and his family, and it was great. 3 bedrooms, 2 baths, very well-equipped kitchen, and a nice balcony with great views to the Allmendhubel funicular and the majestic peaks beyond. My favorite views around Mürren. Access is through the Sports Center and a card for using the pool was provided.