Apple Hub on Twitter: "Full specs including battery capacity and RAM inside the new iPhones have surfaced in regulatory filings. The iPhone XS and XS Max both feature 4GB of RAM, XR
How to Clear the RAM on Your iPhone XS, XS Max, or XR to Fix Problem Apps & Boost Performance « iOS & iPhone :: Gadget Hacks
Used Apple Iphone XS Max 64GB Storage Fully Unlocked Gold Used Good - Walmart.com
iPhone XS and XS Max come with 4GB of RAM, XR gets 3GB RAM, benchmark site
iPhone XS has slightly smaller battery and more RAM than iPhone X - The Verge