Upgrade is an item in Pokémon Go that, at the moment, serves exactly one purpose. It is used to evolve Porygon into Porygon2. This is currently the only way to evolve Porygon, so many trainers with Porygons in their line-up are wondering how to obtain them.
How to Get the Upgrade Item in Pokémon Go
Evolution items are a somewhat rare commodity in Pokémon Go, and Upgrades are no exception. There are a couple methods to getting them, all of which are similar to the methods of obtaining any other evolution item. Still, all the methods scarcely provide Upgrade items, or are rare methods themselves. This means that you shouldn't expect to find an Upgrade item instantly — it'll likely be quite a grind.
Method #1: Special Research
There is one method that always provides you with one Upgrade, and that is to perform the Special Research assigned to you by Professor Willow. The specific research you need to complete is Step Five of A Ripple in Time. This is the second research line he gives you, and can only be accessed by completing all steps in the research titled A Mythical Discovery.
Once you complete Step Five of A Ripple in Time, you'll find that among the rewards is an Upgrade. Unless you're looking to evolve several Porygon, this one Upgrade should be enough!
Method #2: PokéStops Photo Discs
Another way to get this rare item is to spin the Photo Discs at PokéStops and Gyms. It is extremely rare for an Upgrade item to drop from spinning the disc itself (less than one percent). However, if you spin at least one Photo Disc every day for seven days, you're awarded bonus items, one of which is guaranteed to be an Evolution Item. This doesn't necessarily mean you'll receive an Upgrade item, but it greatly increases your chances.
Method #3: Gifts
The last way to get an Upgrade item is through gifts. Every friend you have on Pokémon Go can send you one gift a day. The more friends you have on the game, the more gifts you can receive, and the more likely that one of them will contain an Upgrade. Unfortunately, it is incredibly rare to find an Upgrade when you open a gift. Still, it's possible!
As of now, these are the only methods available to get an Upgrade item, as well as most other evolution items. If new options arise, we'll be sure to update this guide!