domestic · 2h 50m · 1,642 km

Denver to Seattle

4 airlines · 4 aircraft ranked

How we score →

Quick pick

Best economy: strong pick

Fly Alaska. It scores higher across seat comfort and amenities.

If prices are similar, go with this one.

Best first class: close call

Fly United. It scores higher across seat comfort and amenities.

If fares are comparable, this is the better cabin.

Data verified April 2026
1
UA
United FirstUnited · Boeing 737-900ER · 2012 cabinBest on route
recliner · 2-2 · 37" pitchReliable
2.8
Seat 1.2·Amenity 5.1
2
AS
First ClassAlaska · Boeing 737-900ER · 2018 cabin
recliner · 2-2 · 40" pitchReliable
2.8
Seat 1.3·Amenity 5.1

Select two airlines to compare head-to-head

Flying with family

  • Seatback screens on United, Alaska. Southwest, Frontier — bring your own device.
  • Most legroom: Southwest (32"). Least: Frontier (28"). That 4" difference matters with kids.

Route insights

  • In economy, Alaska's Main Cabin (737-900ER) leads the field with a 4.4/10.
  • In first class, United's United First (737-900ER) edges out the field with a 2.8/10.