There are a few bits of information visitors should know in order to use public transportation conveniently. Since most people use buses or Incheon subway system, knowing how to use the Korea Tour Card or operating schedule of the public transportation system means you will not experience any difficulty touring Incheon. In addition, you can easily download a Mobile Korea Tour Card from Google Play Store.

http://koreatourcard.kr/en

Through the Incheon Subway System that visitors may use the subway at Incheon International Airport to visit various places in downtown Incheon. You may purchase a subway ticket whenever you ride. Using the special tour card for foreigners (Tmoney) means visitors benefit with a discount. You may purchase the tour card at an AREX ticket point.
(Incheon Subway Map) https://www.ictr.or.kr/foreign/eng/map/incheon.jsp (Single Use Ticket) Method of purchase : http://www.seoulmetro.co.kr/en/page.do?menuIdx=719

http://www.seoulmetro.co.kr

Source : Incheon Transit Corporation Homepage

Divided into the fast and convenient Incheon Bus, the Local (standard) Bus (Operated in downtown areas), the Express City Bus (Yeongjongdo - Other cities), the Airport Limousine Bus and M Bus (Bound for Seoul). In particular, there are buses bound for Yeongjongdo Island and Seoul, which can be used as conveniently as the subway system. Fares can be paid by card or cash, and vary depending on buses.

https://www.ictr.or.kr

Source: Incheon Transit Corporation Homepage

Visitors wishing to use a taxi in Incheon can get one at any place anytime. There are medium-sized taxis (regular taxi), deluxe taxis and large-sized (jumbo) taxis. Basic fares of the deluxe taxis and the large-sized taxis are higher than the medium-sized taxis, but late night surcharges are not applied.
Both cash and cards (tour cards and credit cards) are accepted.

https://www.incheon.go.kr

Source : Incheon Metropolitan City website

Ticketing : Provision of bus-related information at ticket office and purchase of tickets inside (Next to Exits No. 4 & 9) and outside (Next to Exits No. 4, 6, 7, 8, 11 & 13) of Passenger Terminal 1
Provision of bus-related information and purchase of tickets at the bus terminal in the first basement level in airport Passenger Terminal 2
Since fares and bus intervals may vary depending on areas, make sure to contact information desk in advance.

https://txbuse.t-money.co.kr/

Source : Incheon International Airport Homepage

If you take an airport train from Incheon International Airport, you can get off at a station leading to downtown Incheon.
Make sure to check it out in advance before taking a general train.
It takes about 30 to 40 minutes, and there are at least 2 stations enabling passengers to transfer to Incheon subway system.
Fare : 4,150 KRW ~ 4,750 KRW

https://www.arex.or.kr/

Source : Incheon International Airport Homepage

There are free maglev trains in Incheon International Airport.
There are trains bound for Paradise City Hotel and Yongyudo Island.
Operating hours: 07:30 ~ 20:30 (Adjusted operating hours: 07:30 ~ 09:00, 18:00 ~ 19:00)
Depart from Incheon International Airport Terminal 1 at 00, 15, 30 and 45 minutes at every hour

https://www.airport.kr

Source: Incheon Transit Corporation Homepage