Route guide

Seattle to Denver (SEA-DEN): Nonstop Upgrade & Award Space

United Airlines, Alaska Airlines, Inc., Delta Air Lines, Frontier Airlines, and Southwest Airlines fly nonstop between Seattle (SEA) and Denver (DEN), roughly 127 times a week. Because so many carriers compete on this route, premium seats turn over daily, and upgrade or award space can open and close within hours. 2LNR tracks confirmed availability on every SEA to DEN departure, so you know which flights have space before you book.

Data current as of July 21, 2026, refreshed on an ongoing basis as new schedules and seats are confirmed.

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127
Nonstop flights a week
1,022 mi
Nonstop distance
Free
To get started

Confirmed upgrade & award space on every SEA to DEN departure

2LNR tracks confirmed upgrade and award availability on American, Delta, and Alaska and across 30 airlines, segment by segment, date by date. Open the calendar for Seattle to Denver to see which departures have real space, or watch the route and get alerted when space opens.

See real availability

Confirmed upgrade and award seats on each SEA to DEN departure, checked against live inventory so you know what is open before you book.

Set an alert

Premium inventory turns over fast. Watch this route and 2LNR notifies you when space appears on a date you are tracking.

Plan on the map

See SEA to DEN on the interactive route map, with schedules, connections, and route statistics.

Airlines flying Seattle to Denver nonstop

Carriers operating SEA to DEN nonstop in the current schedule. 2LNR tracks confirmed upgrade and award space on each of them.

  • United Airlines
  • Alaska Airlines, Inc.
  • Delta Air Lines
  • Frontier Airlines
  • Southwest Airlines
See SEA to DEN on the interactive map →

Frequently asked questions about SEA to DEN

How far is Denver from Seattle?
SEA to DEN covers about 1,022 miles nonstop. Flight times vary by aircraft and season; each scheduled departure on this page lists its own times.
Which airlines fly nonstop from SEA to DEN?
United Airlines, Alaska Airlines, Inc., Delta Air Lines, Frontier Airlines, and Southwest Airlines fly the route nonstop. 2LNR tracks confirmed upgrade and award space on each of them.
How many flights a week are there from SEA to DEN?
About 127 nonstop flights a week run between Seattle and Denver in the current schedule, operated by United Airlines, Alaska Airlines, Inc., Delta Air Lines, Frontier Airlines, and Southwest Airlines. Frequency shifts by season; the calendar on this page reflects what's currently scheduled.
How do I check upgrade or award availability on SEA to DEN?
Open the SEA to DEN calendar on this page to see confirmed upgrade and award space by date. You can also set an alert on the Seattle to Denver route, and 2LNR will notify you when space opens. It's free to start.

Never miss SEA to DEN upgrade or award space

Track confirmed availability, set alerts, and book with confidence. Free to start, no credit card required.

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