Commuter train line J38 is located on Arlanda Central (Sigtuna) under Sky City in-between terminal 4 and 5.
Train comes from Uppsala C and Tumba stations via Stockholm Central Station and further to Älvsjö (Stockholm International Fairs).
Commuter trains are called Pendeltåg in Swedish; travel from Arlanda airport to the Central Station of Stockholm. This train takes upto 40 minutes to reach the city.
Ticket can be bought on board or online from Stockholm<a href="https://www.sj.se/" target="_blank"> SJ</a> Website.
Price 125 SEK one way ticket.http://www.sj.se/