Frontier's Economy Bundle offers a carry-on and seat choice, ideal for budget travelers.
Consider Premium Bundle for extra legroom and priority boarding at a small additional cost.
Planning a trip from Denver to Seattle? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.
Based on flight data for the Denver to Seattle route, it's generally cheaper to fly on Saturdays and in the month of January. Here are some tips to help you save money when booking this route:
Cheapest Route: Stick to the direct route from Denver International to Seattle/Tacoma International for the best prices.
Booking Advance: Try to book your flight at least 21 days in advance to get the best rates.
Cheapest Airline: Consider flying with Frontier, as it generally offers the cheapest fares for this route.
Direct or Layover: It's cheaper to fly direct on this route than with a layover.
Route Selection: The direct route from Denver to Seattle is typically the cheapest option.
This feature is powered by ChatGPT: an OpenAI-developed artificial intelligence model trained with KAYAK proprietary data and third-party data not verified by KAYAK.
Low season | January |
---|---|
High season | July |
Cheapest flight | $73 |
Direct departures
Denver Intl to Seattle/Tacoma Intl
Monday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Tuesday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Wednesday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Thursday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Friday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Saturday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Sunday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Direct returns
Seattle/Tacoma Intl to Denver Intl
Monday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Tuesday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Wednesday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Thursday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Friday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Saturday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
Sunday
Alaska Airlines, Delta, Frontier, +2 more
Alaska Airlines, Delta, +3 more
1
2
My flight was delayed 2 hours which led me to lose my connection. As a consequence, I had to spend hours changing flights and hotel reservations to arrange my arrival to Vancouver.
My flight was delayed 2 hours which led me to lose my connection. As a consequence, I had to spend hours changing flights and hotel reservations to arrange my arrival to Vancouver.
No Free Wifi and the flight was a tad late.
The plane was clean. They got us to the destination. It was very difficult to hear the announcements at the gate. The person was speaking way too quickly, and the sound system did not carry to all parts of the seating area at the gate. The flight left more than an hour late, which left many of the passengers missing connections.
The flights left both airports on schedule. The flight from Idaho Falls to Seattle was a typical commuter trip. The flight from Seattle to Maui was not good: It was too long for a flight in a single-aisle plane and too cramped. I kept asking myself if I would ever visit Maui again if airlines continue to run this long flight like a typical short commuter flight. I am not looking forward to the trip home.
The chicken salad was very small, the lettuce was wilted and there was no flavor. The hamburger was excellent.
Mid flight we were bothered by a bee. Kind of odd, but a bee allergy made it a bit stressful. Attendants passed by our aisle during service multiple times. Otherwise, it was fine.
5 1/2 hour flight with no food service or options is inexcusable.
Mostly good. Delayed which in my experience so far happens often with Alaska Airlines. Thank you.
Excellent overall, but had to wait 30 months while taxiing. In fact, I’m still on the plane now!
We received a check-in reminder the day before the flight, and it listed the flight at a later time. Correct flight number, same seats, etc. for 3 hours later. I called the airline to confirm and they had no record of the email. The info was wrong, and we would have missed our flight if we'd assumed it was correct. I want to know where/how we received this incorrect info.
Perfect flight both ways. On time, courteous staff, plane comfortable and cool. Best domestic flights I’ve had in awhile.
Really low quality food especially for an international flight. The crew also was surprisingly unpleasant except couple of ladies. I know we were not in first class but that’s no reason to treat customers as less.
Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.
Crew was good. The reservation got mixed up and they didn't have my TSA number. I am also a Silver Medallion and wasn't able to use Sky Priority.
Delta made it easy, comfortable and timely. The crew was fantastic.
This route with Delta always has delays or is cancelled. Aircrafts seem smaller and older. I fly Delta quite a bit - haven’t had issues with the international flights. But this route has always been the troublesome one
Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate
Mechanic delay in addition to a 2 hour change in takeoff time was frustrating.
Delayed due to thunderstorms and no in-flight service due to rough weather — both of which are out of Delta’s control. Flight was good overall.
The seats got pretty uncomfortable pretty fast. The armrests are bigger than on other planes, so I had less room in the actual seat. My butt hurt by the end of the flight. :/ comfort was the primary issue. The crew were fantastic!
First class ticket. They ran out of food and I sat hungry watching the others eat
They we able to seat my companion and I next to each other. Plane’s temperature was very cool. Willl be more prepared on return trip.
All was good and they were able to seat my travel companion next to me. Thank you.
Like the ample leg room. May as well not bother with snacks if it's only a two ounce bag of pretzels. Didn't use the entertainment option. Was there one?
What an amazing flight. I haven’t experienced this level of service in a flight in years. This will be the only way to fly to Hawaii for me in the future.
Kayak sold me a ticket after check in time. Could not check in. Could not get on flight.
Love you guys are so friendly and kind and wonderful
Agents talk too fast over intercom. I know it’s memorized and we’ve all heard it before. Just slow down a little. Stop charging for checked bags. I was pleased to get my bags promptly at each end of my flight.
Everything was great except having to check in at Alaska. That was a surprise and took extra time and effort. Should have been explained somewhere maybe on the HA electronic ticket.
It was clean and the crew was great. I wish the chairs could recline just a little more and you would provide small pillows for people with bad backs. My back is fused and a little support would be great.
it was so bad. I tried to board my flight from vancouver to saskatoon. And to my surprise they did not board me cause the flight was changed and no email was send to me. and on my boarding pass which i got from seattle says different flight. I did not knew anyone from Vancouver, air canada crew was rude, i asked for today flight but they were rude and i had early morning dental appointment in saskatoon. I was so much in pain and my whole day is wasted today. and i suffered alot. They did provide me hotel but they did not provide me any food. I am really really disappointed first time had so bad experience with air canada. I may think twice to book it again. If i can get any reply or any composition that would be great. Thanks
Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.
Great experience…left a bit behind schedule but made up fir that in the air and landed 10 minutes early 😁
Electric plugs didn't work. Entertainment system wasn't working
The design of the light switch on the arm rest is ridiculous.
leg space better than expected. two washrooms for one plane isn't enough.
The gate attendant let me walk right by her with a bag too big for the overhead compartment
The seats on this flight were almost roomy enough to be the basic amount needed for human existence. I think my favorite part of this flight was it landed at an A gate, which was the most palatial part of Sea-Tac I've ever seen - a massive improvement from the S gates.
Overall, it was a good experience. Boarding was good and there was plenty of overhead bin space for everyone’s carryons (even when we boarded toward the end). Only improvement would be to offer trash service more regularly.
David went above and beyond to make our flight the best that it could be
What I expected, nickeled and dined and a frontier flight attendant loudly complained about her job and lack of communication as she headed to the gate on her cell phone. Not professional.
I’m not gonna fly Frontier Airlines because booking is not an option. No water or food is for high price, not equipped for health emergency incompetent crew for emergency services. Cheap airline shows it is cheaper in all service categories. Boarding is the best of all airlines!
Very bad! No good service delayed my second connection flight
Frontier is terrible. Paid for exit row, not given exit row, refused to refund fee.
2 hour delay due to late plane, wrong size plane causing overbooking, and people getting off and on the plane after boarding was completed.
The worst. We never made our connection and they did absolutely nothing to help us at the airport.
I never got to experience the flight because they delayed my first flight and I missed this one. Then Frontier didn't want to help me rebook a flight to get me to my final destination.
The Boarding process in Denver was chaotic, and since the line was so long, we were lined up very far from the gate. If there were any announcements from the gate staff, we didn't hear them. The flight attendants were spectacular. The only negative part of the flight was sitting by a 2 1/2 year old who was unruly and unfortunately had parents that matched his behaviors. Also, the restaurants in Denver on the E concourse, they didn't have food (passengers could only order 1 item on the entire menu) or the restaurants had 12-14 people waiting for orders to be prepared and another 6 people waiting to order. If you have a layover in Denver and need to grab food, be prepared to visit the shops with pre-packaged sandwiches, or you can visit another concourse but it may take a while to transit throughout the airport.
Everything went as planned. Crew was great. Seats were still not that comfortable.
they delayed my flight which ended up, causing my layover flight to leave without me, resulting in me missing a flight and having to stay overnight in Houston international. I got no compensation other than a flight to my original location only a day later. i’ve never experienced such a unprofessional situation
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