UPC or "Universal Product Code" consists of 12 numeric digits, that are uniquely assigned to an item and used extensively for retail packaging.
Oftentimes, product pages for retailers will only display their own unique product codes (i.e. "Walmart#" on Walmart.com or "ASIN#" on Amazon.com) but if you have the exact UPC for a product, you can easily type/paste it into Google search or into the search bar on a competitors website to compare the price of that identical product. From there you can easily find the best deal while comparing stores.
To find the UPC on Walmart.com:
1. You need to be on the walmart.com product page for your item
2. Next, you hit Control “U” (This opens up the source code of the page, stay with me here!)
3. Then hit Control "F" (This opens up the search function)
4. Type UPC in the search function bar, and hit enter
5. Now, you'll see UPC highlighted a few times and beside one of the first results will be the UPC number (12-digits) - now you can copy or write down that code !
To find the UPC on Target.com:
1. You need to be on the target.com product page for your item
2. In the "about this item" area below the photo of your item, click "details"
3. There you'll see the UPC and can copy it
To find the UPC on Amazon.com:
1. You need to be on the amazon.com product page for your item
2. Scroll down until you find the "product information" section
3. Rarely is the UPC listed here but find the ASIN code instead (i.e. B01JHON2XG)
4. You can copy this ASIN code and input into a free ASIN to UPC converter website to find the UPC you need! I currently use ASIN to UPC but i'm sure there are plenty so browse around.
Cheers!