United States · Seattle
Seattle-Tacoma International Airport (SEA) Online Check-in
Pacific Northwest's primary airport and Alaska Airlines' main hub. Single connected terminal with Concourses A–N. Major Asia-Pacific gateway with Delta + United operations.
Now at Seattle-Tacoma International Airport
- Security wait (today, avg) 18 min
- Disruption No reported disruption
- Weather impact Clear, 14 °C
Quick information
Airlines we cover at Seattle-Tacoma International Airport
Seattle-Tacoma International Airport hosts about 35 airlines in total. We have terminal-specific check-in pages for the 1 listed below. Pick yours to see counters, bag-drop, and online check-in details.
How to check in for a flight from Seattle-Tacoma International Airport
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Check in online before you leave home
Most airlines open online check-in 24–48 hours before departure. It saves time at the airport and avoids airport-counter fees on low-cost carriers.
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Arrive at the right terminal
SEA has 3 terminal(s). Check your airline's terminal in the table above before you set off.
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Drop off checked baggage
Counters typically open 2 hours before departure and close 40 minutes before. Use self-service bag-drop kiosks to save time.
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Pass security
Liquids must be in a single transparent bag, max 100 ml each. Laptops and large electronics out of bags. Submit your security wait time below to help others.
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Reach your gate on time
Most airlines close the gate 20 minutes before departure. Allow 5–15 minutes to walk from security to the gate.
Tips for Seattle-Tacoma International Airport
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Light Rail is cheap + fast to downtown
Sound Transit Link Light Rail: $3.50, 38 min direct from SeaTac to downtown Seattle. Trains every 10 min during the day. Stations: Westlake (downtown), Capitol Hill, University of Washington.
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Concourses A–D in main, N + S satellites
Main terminal Concourses A–D (most domestic). Satellites: N Terminal (domestic, served by underground train) and S Terminal (international, also underground train). Allow 15 min for satellite transfers.
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Boeing Customer Tour from Paine Field
Boeing's main factory is at Paine Field (PAE), 30 km north of SEA. Public Customer Tour available. Many travelers visit on Seattle layovers.
Popular destinations from Seattle-Tacoma International Airport
Frequently asked questions
Which terminal does Alaska Airlines use at SEA?
Alaska Airlines primarily uses Concourses C and D in the Main Terminal, plus N Satellite Terminal for some flights. Domestic concourse C; west coast and Alaska routes from N.
How do I get from SEA to downtown Seattle?
Light Rail (Sound Transit Link): $3.50, 38 min direct. Uber/taxi: $35–50, 25–40 min. Bus 124: $2.75, 90 min.
Is SEA a primary Asia-Pacific gateway?
Yes — SEA has direct flights to 7+ Asian cities (Tokyo HND/NRT, Seoul ICN, Beijing, Shanghai, Taipei, Singapore via Vancouver). Major Asian carrier presence.
Official sources
The check-in details on this page are sourced from each airline's website. For terminal layout, opening hours, and ground-side services, see the Seattle-Tacoma International Airport official site below.
- Wikipedia: Seattle-Tacoma International Airport — Editorial overview, history, statistics.
- FlightRadar24: SEA live data — Live flight arrivals, departures, and delays.
- travel.state.gov — Up-to-date entry requirements and security guidance for United States.