Venice in 2 days

We also had 2 days in Venice and managed to do Burano and the major sights in Venice. In Venice, St Marks, Doge's palace, Correr museum, up the bell tower , visiting San Giorgio Maggiore just across the grand canal from St Marks, Frari church and the scuolo San Rocco, la salute church, crossing both the Rialto and Academia bridge and a grand canal cruise on a slow vaporetto with a Rick Steves audio guide was what we managed in a hectic 2 days.
Choose one of the lagoon islands, Burano is more picturesque with pastel colored houses lining it's canals. Murano is more known for its glass work. So choose one and u can do it in the morning and return to Venice by lunch time.
A lot depends on how much u can walk in Venice so see how much you can accomplish in 2 days.

Hope it helps.
Have a great trip

It takes the day to do those 3, and it's beautiful. The question is, do you want to spend the whole day, when you only have another day for Venice.
Make sure when piazza san marco, the palazzo is done, to walk away from there as it's way to crowded, and just walk, visit inside of churches, small piazzas, stop for an expresso, enjoy the incredible beauty of that city. Everywhere you breathe art and beauty. It's just magnificent.
If you like renaissance art, Accademia museum is very nice.
I would do my Venice walk the first day, then you'd know if you've done what you wanted.
You'll know then if you have the whole day the day after to do the 3 other islands.
Enjoy.
Claude

Yes, Murano, Burano and Torcello can be done in one day. But, you will have to get an early start in the morning and plan on using just about all day.

Murano and Burano are rather "secondary" when your main destination is Venice. Don't waste a whole day of your Venetian vacation just to go to Murano and Burano - enjoy the sites/sounds/tastes where you already ARE.

I personally believe 1 day to see the sights in Venice is just way too short. Each neighborhood has a different character and vibe and there are so many worthy sights.

A few tips for San Marco - entrance is free although some interior areas cost money. You must reserve an entrance time which can be done online for a nominal fee. The alternative is to wait in a queue, possibly a long one, to be issued an entrance time for later in the day. The ceiling is lighted from 1130-1230 everyday. Anything larger than a large shoulder bag/purse must be checked at the baggage check across the piazza.

Finally, if you are able-bodied and have no mobility issues, you can usually walk from Ferrovia to Piazza San Marco in about the same amount of time that the water bus takes. And the stops at Ferrovia and San Marco can be VERY crowded.

If you're considering heading out to those islands, I would plan that as your Day #2. My reason is that you will have a much better idea after the first day if you're willing to give up the 2nd day away from Venice. We've been to Venice three times for several days and only took a morning trip to see Murano - just too much fun to be in Venice!

Thanks so much everyone. That was really helpful.