Uppsala or Vaxholm on a Sunday?

Things are generally open on Sundays in Sweden, sometimes with slightly reduced hours. If there is something specific you have in mind, just check online. Either place is a nice day trip - Uppsala has more to see and do. It is a lively university and cathedral city and you can also visit rune stones and nearby Gamla Uppsala (ancient burial /Viking site); Vaxholm has the scenic ferry trip and is more of a quaint harbor village plus the fortress - though you'd probably want good weather guaranteed. So just depends if you want the historic student city feeling + Viking history or small town archipelago atmosphere.

We went to Vaxholm once, many years ago, on a Sunday and had a wonderful time. The ferry ride was beautiful and we enjoyed walking around the island and having lunch outside. I haven’t been to Uppsala so can’t compare but Vaxholm was very nice. This was early May so still a little chilly but otherwise good weather.

Hi there, I saw an interesting answer to your question about taking the ferry to Vaxholm here - https://community.ricksteves.com/travel-forum/sweden/archipelago-tours-private-charter-vs-stromma.

These 2 destinations are quite different. Though I live in Uppsala, if you're not going to get out into the archipelago, I might choose Vaxholm for the ferry ride. However, if you're into cathedrals, excellent high tea, ancient Viking ruins & gorgeous architecture, choose Uppsala. There's a 12:30 English language tour of the cathedral daily. (June 22 to Aug 16.)