Is it possible?

[JAY-ROD]

Is it possible to do both parks in one day if you have front of the line access?

 

[JoeCamel]

Sure, if you just want to check it off. If you want to see the thought and execution that went into building the attractions then budget enough time to appreciate it. Certainly 2 or better three days would allow you to see most of what they built for you.

 

[BubbaQuest]

Maybe. If you're a coaster fan and just want to hit the highlights, probably. If you want to experience all of Potter, probably not.

Keep in mind the Express Pass does not give you front of line access to any of the Harry Potter attractions. On a slow day, the key Potter attractions could take 2 hours (1 hour for Gringotts, 20 minutes for Hogwarts Express, and 30 minutes for Forbidden Journey). On a busy day, this could easily be 4+ hours. And this excludes a lot of the stuff that makes Potter great like Ollivanders, interactive wands, and butter beer.

The Express pass will help with some other rides, mainly Spiderman and Minions, but at that point I think it would feel more like running a marathon than having fun at the park. It is a lot of walking just to circle both parks in one day.

For my first trip (pre Diagon Alley), I had an Express Pass. That worked well for seeing all of Islands of Adventure in one day. I could have run through the Studios park in the evening to see the highlights but decided to go back to Hogwarts instead. With Diagon Alley and Moe's Tavern, I can't image doing both parks in one day now.

 

[EngineJoe]

Depends when you go of course.
For Harry Potter you could do the single rider lines which are significantly faster (like 60 min wait compared to 10 min wait).
The biggest obstacle however is just walking distance IMO. Because of how the parks are designed you basically have no choice but to walk around the lakes in each park and that means you have to do all the rides in that order to maximize time and you have crowds of people slowing you down.

I think it's possible to do but you would probably feel really rushed unless the park is completely empty.

 

[EngineJoe]

I think it also depends if you've done the park before. I find that with the Disney parks I've done everything so many times that I can manuever quickly with my internal map.

Also each extra person in your party exponentially slows down your movement. If you have 8 people in your party then someone is always stopping to use the bathroom or eat or can't make up their mind on what ride to do.

 

[PinnySmart]

Even with Express pass on a busy day you can't do it. Express pass isn't good for the Potter stuff or Minions maybe transformers? You would have to skip some major attractions to get it all in in one day.

If you're just a Potter fan and that's all you want to see then a park hopper one day would do it. Depends what exactly you want to see? From the sounds of it I'm not sure you realize what exactly is at Universal Orlando? Have you looked over the park attractions and picked out must sees?

Express Pass can most certainly be used at Despicable Me Minion Mayhem and Transformers.