DEN - SEA

$106 Find Cheap Flights from Denver to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Denver to Seattle departing on 7/11. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Seattle.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Seattle.
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 24% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$165
Typical prices: $257-$146
Frontier
Mon 10/12Thu 10/15
DEN - SEA • Non-stop
Cheapest one-way
$106
Typical prices: $137-$231
Frontier
Sat 7/11
DEN - SEA • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
Frontier Economy Bundle adds a carry-on and seat choice for budget value.
Delta free Wi-Fi and Alaska Premium Class add comfort on this short route.
Expert advice
Expert advice
+1
+1
Expert advice
Expert advice
+1
Top airlines
Cheapest • from $165 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
You can fly direct with Alaska Airlines, Delta and others. Average duration is 3h 01m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Avoid delays
Most punctual • 86% on-time
Best time • Fewest delays
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 35% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 36% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Seattle!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Denver to Seattle (DEN-SEA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Denver to Seattle that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Denver to Seattle

Mon, Oct 12 - Thu, Oct 15
Frontier Logo
7:45 am - 9:51 am
DEN
-
SEA
3h 06mnonstop
Frontier Logo
7:41 pm - 11:34 pm
SEA
-
DEN
2h 53mnonstop
$165Frontier
Sun, Oct 11 - Wed, Oct 14
Frontier Logo
7:45 am - 9:51 am
DEN
-
SEA
3h 06mnonstop
Frontier Logo
7:41 pm - 11:34 pm
SEA
-
DEN
2h 53mnonstop
$176Frontier
Tue, Oct 13 - Thu, Oct 15
Frontier Logo
7:45 am - 9:51 am
DEN
-
SEA
3h 06mnonstop
Frontier Logo
7:41 pm - 11:34 pm
SEA
-
DEN
2h 53mnonstop
$177Frontier
Mon, Oct 12 - Wed, Oct 14
Frontier Logo
7:45 am - 9:51 am
DEN
-
SEA
3h 06mnonstop
Frontier Logo
7:41 pm - 11:34 pm
SEA
-
DEN
2h 53mnonstop
$178Frontier
Sun, Aug 16 - Wed, Aug 19
Frontier Logo
9:13 am - 11:20 am
DEN
-
SEA
3h 07mnonstop
Frontier Logo
7:41 pm - 11:36 pm
SEA
-
DEN
2h 55mnonstop
$180Frontier
Tue, Sep 8 - Mon, Sep 14
Frontier Logo
7:45 am - 9:48 am
DEN
-
SEA
3h 03mnonstop
Frontier Logo
7:00 am - 10:51 am
SEA
-
DEN
2h 51mnonstop
$184Frontier
Sun, Aug 16 - Wed, Aug 19
Frontier Logo
7:00 am - 5:51 pm
DEN
-
SEA
11h 51m
1 stop
Frontier Logo
7:41 pm - 11:36 pm
SEA
-
DEN
2h 55mnonstop
$186Frontier
Fri, Aug 28 - Wed, Sep 2
Frontier Logo
8:44 am - 6:58 pm
DEN
-
SEA
11h 14m
1 stop
Frontier Logo
7:41 pm - 11:36 pm
SEA
-
DEN
2h 55mnonstop
$188Frontier
Sat, Sep 19 - Thu, Sep 24
Frontier Logo
10:29 pm - 12:27 am
DEN
-
SEA
2h 58mnonstop
Frontier Logo
7:41 pm - 11:34 pm
SEA
-
DEN
2h 53mnonstop
$194Frontier
Tue, Aug 11 - Tue, Aug 18
Delta Logo
1:21 pm - 3:23 pm
DEN
-
SEA
3h 02mnonstop
Delta Logo
8:07 pm - 11:58 pm
SEA
-
DEN
2h 51mnonstop
$195Delta
Booking Insights

KAYAK's insights & trends for Denver to Seattle flights

Get data-powered insights and trends into flights from Denver to Seattle to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Denver to Seattle?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Denver to Seattle departing in October.

What’s the cheapest day of the week to fly from Denver to Seattle?

The average price of all round-trip flights from Denver to Seattle clicked on KAYAK for each day over the last 12 months.

For Denver to Seattle, Friday is the cheapest day to fly on average and Tuesday is the most expensive. Flying from Seattle back to Denver, the best deals are generally found on Friday, with Sunday being the most expensive.

What is the cheapest month to fly from Denver to Seattle?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Denver to Seattle, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Denver to Seattle is January, where tickets cost $138 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is $279 and $267 respectively.

How far in advance should I book a flight from Denver to Seattle?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Denver to Seattle, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Denver to Seattle, you should book around 3 weeks before departure, which saves you about 35% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 4 weeks before departure.

Expert advice

Expert advice for your flight from Denver to Seattle

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Frontier, Delta and United Airlines

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Harriet Baskas

Harriet Baskas

Expert on Alaska Airlines, DEN and SEA

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Blane Bachelor

Blane Bachelor

Expert on Southwest

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

KAYAK's tips to save more on a Denver to Seattle flight

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.

AI-powered; AI can make mistakes.

Good to know

Low seasonJanuary
Cheapest flight$106
Best time to beat the crowds with an average 37% drop in price.
Most popular time to fly with an average 23% increase in price.
Flight from Denver to Seattle

When to book flights from Denver to Seattle

Are your dates flexible? Find out the best times to travel from Denver to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Flights from Denver to Seattle: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew the route from Denver to Seattle 
Verified travelerFlew with Delta
DEN
-
SEA
Jun 2025
If you are on the left side of the plane you should spot Mt. Rainer on your way into Seattle.
Verified travelerFlew with Alaska Airlines
DEN
-
SEA
Oct 2024
Go early, it’s a big airport. There are two TSA screening areas, one might be more crowded than the other. From checking it to the gate give yourself at least 20-30 minutes to get there.

FAQs for booking flights from Denver to Seattle

  • Does Denver International Airport offer any amenities for pets or service animals?

    In addition to having several indoor pet relief areas in Terminals A, B, and C of Denver International Airport, there is an outdoor relief zone that can be found in Jeppesen Terminal. Each of these areas contains grass, secure fencing, soap, running water, and waste disposal bags. There is also a 4 Paws Pet Resort that is connected to the airport via a free shuttle and provides boarding and grooming services for animals.

  • Do any airlines have lounges for their customers at Denver International Airport?

    Both American Airlines and Delta Airlines have lounges located in Concourse A of Denver International Airport in the Departures terminal. Additionally, United Club has two lounges that can be found in the airport’s East Wing and West Wing, and they also offer an annual membership program.

  • Are there any shower facilities at Seattle-Tacoma International Airport?

    To take a quick shower after your plane has landed, go to the Delta Airlines Sky Club between Gates S8 and S9 in Seattle-Tacoma International Airport. This lounge allows travelers to buy entry tickets at the door and has shower stalls, hairdryers, towels, and toiletry kits that contain shampoo and soap.

  • Where can I rent a car at Seattle-Tacoma International Airport?

    To rent a car from Seattle-Tacoma International Airport, go to the Rental Car Facility by taking the free 24h shuttle that departs from outside of the Arrivals terminal. Several major rental companies can be found in this center, including Budget and Enterprise, and most of them keep their cars on-site or provide free transportation to their parking garage facility.

  • Which is the best way to get to downtown Seattle from SEA?

    The distance from SEA to the city center of Seattle is approximately 13.8 miles. A light rail provides the best way to travel between these two distances, taking about 40min to complete the journey. Another option is to hop onto the airport shuttle, which takes around 1h to commute from SEA to the city center of Seattle. If you want to get there in under 25min, a taxi is handy.

  • Which family-friendly amenities are the SEA?

    Seattle-Tacoma International Airport (SEA) has rooms where moms can pump or breastfeed in privacy. These facilities are situated in Concourse D on the lower level of D Annex and Concourse N on the Mezzanine level. Also in these rooms are comfy chairs, electrical sockets, and sinks.

  • Which airline allows pets on board from DEN to SEA?

    Passengers flying American Airlines will be glad to know that the carrier allows you to bring pets like cats and dogs in the cabin when traveling from DEN and SEA. Remember to carry their health documents and vaccination certificates; you must restrain them in their cages during the trip.

  • Where can I withdraw money at SEA?

    Various banks and credit unions run their ATMs at SEA, making it easy for arriving travelers to recharge their wallets. They’re situated on Concourse A and in the Baggage Claim.

  • What is the cheapest flight from Denver to Seattle?

    In the last 7 days, the lowest price for a flight from Denver to Seattle was $106 for a one-way ticket and $165 for a round-trip.

  • Do I need a passport to fly between Denver and Seattle?

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

  • Which airports will I be using when flying from Denver to Seattle?

    Denver and Seattle are both served by 1 main airport. You will leave Denver from Denver Intl and will be arriving at Seattle/Tacoma Intl.

  • Which airlines offer Wi-Fi service onboard planes from Denver to Seattle?

    Alaska Airlines, JetBlue, Delta, and Air Canada offer inflight Wi-Fi service on the Denver to Seattle flight route.

  • Which aircraft models fly most regularly from Denver to Seattle?

    The Airbus A321neo is the aircraft model that flies most regularly on the Denver to Seattle flight route.

  • Which airline alliances offer flights from Denver to Seattle?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between Denver and Seattle, with Star Alliance being the most commonly used for this route.

  • On which days can I fly direct from Denver to Seattle?

    There are nonstop flights from Denver to Seattle on a daily basis.

  • Which is the best airline for flights from Denver to Seattle, Southwest or Alaska Airlines?

    The two airlines most popular with KAYAK users for flights from Denver to Seattle are Southwest and Alaska Airlines. With an average price for the route of $279 and an overall rating of 8.0, Southwest is the most popular choice. Alaska Airlines is also a great choice for the route, with an average price of $287 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from Denver to Seattle?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Denver to Seattle.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Denver to Seattle?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from Denver is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Denver to Seattle?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Seattle with an airline and back to Denver with another airline. Booking your flights between Denver and SEA can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Denver to Seattle?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Seattle from Denver up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Denver to Seattle

  • Looking for a cheap flight? 25% of our users found flights on this route for $152 or less one-way and $270 or less round-trip.
  • Both United and Delta Airlines offer flights from Denver to Seattle that provide travelers with comfortable seats and additional legroom, as well as in-flight entertainment. If you would like to check your suitcases for free and receive complimentary snacks, opt for flying with Southwest Airlines instead.
  • If you’re traveling to Seattle for an important meeting or workshop, stop by the business center that is near the B Gates of Denver International Airport (DEN). This center provides guests with private workstations, copying services, shipping supplies, and access to the airport’s high-speed Wi-Fi.
  • To pass the time before your flight from Denver to Seattle begins boarding, go to the ZooX Public Internet Kiosk Systems in the Jeppesen Terminal of Denver International Airport. These booths allow travelers to play video games for $0.15 per minute, with a minimum payment of $3.
  • Hoping to leave one of your bags at the airport while you explore? Go to the Smarte Carte Baggage Storage desk between baggage carousels 12 and 13 of Seattle-Tacoma International Airport (SEA). In addition to offering baggage storage for $8 to $22 per item per 24h, this center also has notary and fax services.
  • To de-stress after a long day of travel, stop by the Massage Bar near the N gates of Seattle-Tacoma International Airport. 15m massages start at $18, with 30m massages costing $43. You can also have an express foot massage for less than $20.
  • Travelers with scheduled early morning flights via Denver International Airport (DEN) should consider spending a night in one of the numerous hotels around this facility. Typically, such facilities provide complimentary cars to and from the airport, making it possible to be at the terminal in time for your flight. Such hotels include Embassy Suites by Hilton Denver International Airport.
  • Denver International Airport (DEN) features only one terminal, the Jeppesen Terminal, complimented by three Concourses, A, B, and C. This terminal includes check-in facilities, security checkpoints, customs, immigration, and luggage claims. The concourses are reserved for departures. Movement between the terminal and the concourses is via The Automated Guideway Transit System, which departs at a 5-15min interval.
  • Families traveling using Denver International Airport (DEN) will be glad to know that the property caters to the needs of moms and the smallest of the family members. Lactating and nursing rooms are situated after security in every concourse from where you can pump and breastfeed in privacy. Also, the rooms feature sinks, power sockets, and comfy seats.
  • Suppose you wish to say a prayer before departing from DEN to Seattle-Tacoma International Airport (SEA). In that case, you’ll find a prayer room at this facility. Situated away from the noisy terminals, this sacred sanctuary sits in Jeppesen Terminal, Level 6 East, and it runs between 4 am and midnight every day. The room includes an Islamic Masjid and an inter-faith chapel.
  • If you’ve arrived at DEN and wish to drop off your car before flying out to Seattle-Tacoma International Airport (SEA), you won’t have a shortage of options to meet your needs. DEN offers different levels of parking, including garage, economy, short-term, and long-term. Economy parking is located on the east side of Jeppesen Terminal, and shuttles depart every 10min to get you there.

Prefer to fly direct from Denver to Seattle?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Denver Intl to Seattle/Tacoma Intl.
Find which airlines fly direct from Denver Intl Airport to Seattle/Tacoma Intl Airport, which days they fly and book direct flights.

Direct departures

Denver Intl to Seattle/Tacoma Intl

Monday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Tuesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Wednesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Thursday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Friday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Saturday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Sunday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

See more direct flights

Direct returns

Seattle/Tacoma Intl to Denver Intl

Monday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Tuesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Wednesday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Thursday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Friday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Saturday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

Sunday

Alaska Airlines,Delta,Frontier, +2 more

Alaska Airlines,Delta, +3 more

See more direct flights

Reviews of the top 5 airlines serving from Denver to Seattle

 
See real verified KAYAK customer reviews for airlines flying from Denver to Seattle. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Denver to Seattle? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4260 reviews
8.6Crew
8.1Boarding
7.5Entertainment
7.0Food
8.0Comfort
Airline reviews

The first time I flew in the extra legroom section. It was difficult to notice a difference. I had bad luck with my neighbors. The crew was okay. Southwest has reduced the live TV options.

4.0 OkayAnonymous, May 2026
MDW - LAX
Read more Southwest reviews

The first time I flew in the extra legroom section. It was difficult to notice a difference. I had bad luck with my neighbors. The crew was okay. Southwest has reduced the live TV options.

The flight was smooth. The Southwest experience has degraded overall, but this one was okay.

No gluten free snacks. Seats felt worn or bare bones even though it was a new 737 MAX 8.

One major problem that was very unprofessional and uncalled for. Plane landed and we had to wait 20 minutes to get off the plane since they were waiting for someone to come to the gate to drive the jetway. Southwest couldn't have someone available and waiting for the plane to land? Is there only one person in Hobby airport who knows to drive the jetway? Was he at lunch? In the bar? Uncomfortable and uncalled for!

The checking experience in Orlando was terrible, almost missed the flight. Too many travelers and Southwest completely understaffed.

I'm glad it wasn't only 75% full because I could get a good seat

if I was good. Not happy that I have to pay extra money to get the seat I need for lake room, but I guess that’s a sign of the times.

Seats were very comfortable. They tilted back. Drinks and snacks were free and served 3 times. Attendants were awesome.

Plane was clean and comfortable. Flight attendants and gate staff were professional, friendly and efficient. Boarding and deplaning were orderly and efficient. All in all, the typical excellent Southwest experience.

Truly terrible. Will never willingly fly southwest again. Seats are worse than before they switched to assigned seating. One flight attendant was the opposite of helpful (rude, unhelpful, dismissive, and as my stranger seatmate said unprompted: a total prick). This caused me, 15 minutes into the flight, to book an alternate return flight home on a competing airline (first class 1.2k purchase instead of my existing planned flight) just so I would not have to ever be on that aircraft, with that terrible service person, with those horrific seats ever again.

I flew standby with my two children and completely forgot it was Memorial Day weekend. We tried to fly from PDX to YVR. Unfortunately, after four attempts, we gave up and tried SEA instead after the holiday. The ground crew was very helpful, checking us in and accommodating us when we were finally able to get on a flight. The sad part was that they accidentally loaded one of my suitcases on the Vancouver flight without us during one of our attempts to get on a flight, even though it had a standby tag on it. I filed a report with baggage services, and thankfully, it was returned to PDX the following day. AS was in touch with us and updated us on the process of returning the luggage to the USA.

It was efficient and great. DIA took a while to let us leave but other than that it was great.

90 minute delay boarding the plane, 45 minute delay on the terminal, 2 hours late arriving, currently waiting 45 minutes on the tarmac for a gate so we can BEGIN deboarding. Absolute mess. Definitely will be my last flight with Alaska.

Extremely professional crew there are very friendly and first class. Everything worked well on the plane. Food was to be expected. Drinks were very good. Shout out to Charlie in first class who was an excellent flight attendant.

The plug in for my charger didn’t work and on my return flight back home the passenger in the window seat got up seven times

The boarding pass had no gate published and there are many fewer large boards with arrivals and departures I almost missed my flight trying to find the gate

Everyone was so kind, flight was wonderful, check in and baggage were easy. Thank you guys so much for a great trip

For such a long flight, Tampa to Seattle, was shocked to learn that no food was served. Also, there were no TV monitors to be able to watch a movie.

The staff at the check-in counter was responsive to the long queue and intervened to redirect the traffic: foreigners can't complete check-in without human agents; that is the real line which moves quickly enough. On-boarding and off-boarding were smooth and civilized. Overall the operations were efficient and the experience was pleasant.

Ok, but nothing special. Long flight with no blanket/pillow set.

No service flight that took 5 hrs and a stop at an unscheduled airport. Crew and pilots did their jobs

Clean planes and not take my comfort class seat away.

Weather caused a long delay, but the efficiency and updates from the pilot were helpful. We were able to make our connection fortunately.

Planes were clean, no water or snacks on either flight.

Free & relatively fast Wi-Fi. Would've liked a wider drink selection.

Much better than I expected. I had an economy ticket so I was really happy the flight was so comfy and the service so generous. Passengers were all polite too.

Flight was delayed, we could have been notified earlier and in a consistent manner. App was not refreshing for another passenger to get the latest flight status. We could have stayed and waited at the hotel instead of waiting at the airport had we known the flight was going to delayed for more than 5 hours. The toilet is too tight, and needs to be cleaned more frequently (every hour). The entertainment screen froze, the touch screen not responding to touch. We were upgraded to comfort, it is more comfortable than regular economy seats.

It was fine. 55 minute flight. No snacks or beverage service offered. Boarding went smoothly and my walker was waiting for me on the jet way.

My flight was cencaled due with the bad weather on Sunday the crew was poorly mistaken my luggage supposed depart with my flight instead I didn’t have my luggage for almost 3 days the website is poorly respond to my complain until I have someone to do it my connection smooth their not even respon or email me even the have my luggage

8 hours late and the plane smelled like urine, that smell in the morning when your child wet the bed in the night.

It was a short flight so I was expecting too much

Had a one hour delay due to mechanical issue. I didn’t think I’d be able to make my connecting flight, but they waited for me and greeted me when I arrived to help things run smooth.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Was great in general, try to respect time and excuses when slight changes have been made, appreciated!

Really hard landing... as in slammed into the runway then hit the brakes really hard ...

Every staff member was professional, friendly and courteous. The pizza twist was ok. It was warm but too much dough.

Wonderful in-seat entertainment with seatback screens and huge selection of quality movies. The ability to bluetooth connect headphones was amazing.

Smooth and easy boarding, comfortable for the entire 5 hour flight, and the seat back entertainment was great! I appreciated all the features, from location info and maps, movies, the ability to connect with Bluetooth headphones, and good selection of movies. Food was good, normal airline snacks (I didn’t purchase anything)

Flight left on time and we arrived 25 minutes early! There was a gate available when we arrived so early on a busy Sunday afternoon! Flight attendants came around twice with the drinks cart.

Sitting on the runway after we land for almost two hours! Not sure if we should blame United or Just Dumpy Vance.

There weren't enough employees at check in took awhile to get bags checked. There wasn't a wheel chair for me, I was sent to someone who turns out to work for a different airline, if My flight hadn't been delayed I probably would have missed my flight as it was, by the time I arrived at my gate, they started boarding in about 15 minutes. I don't know who took me to my gate, definitely was not the normal people who take passengers to the gate. I'm guessing she may have been in a management position. I wish I knew her name, she went beyond to help me. With that said everyone was kind, and were doing the best they could. So, I choose to say it was an Adventure, stressful start, but good. In the end went well. The situation was not only difficult for passengers but the employee's.

The staff at the check in counter was so rude. Made you feel Incompetent

Frontier scheduled a 40 minute connection in DEN. What they failed to mention was that they “close the doors” 20 mins prior to departure, which means you only have 20 mins. Not enough time. Possibly against DOT regulations. Filing complaint.

Flight was scheduled at 9:40pm. Got delayed to 10 am, the next day. crazy

The bag check, flight check-in, and onboard experience convinced my wife and me that we will actively go out of our way to avoid flying Frontier Airlines in the future. At bag check, we were informed that check-in could only be completed via the Frontier mobile app. Unfortunately, the app was extremely frustrating—sending us through repetitive, confusing loops that repeatedly forced us to decline add-on services with nearly every click. While most airline apps upsell, this one felt intentionally exhausting. As the process dragged on, we became genuinely concerned that my phone battery would die before check-in could be completed. We approached the bag check staff—who were standing together talking—and explained both our frustration and our predicament. They laughed. Later, my wife described the interaction as “gaslighting,” which felt accurate. We were then informed it would cost $25 per person simply to have our boarding passes printed. From that point forward, the tone of the experience was consistently hostile. The bag check employees were condescending and combative, behaving more like bullies than customer service staff. Unfortunately, that same attitude continued onboard. One flight attendant argued with me when I attempted to stow my backpack in the overhead bin. I explained that we had each paid $75 to check our bags specifically so we would not need to use carry-on space and could have adequate legroom. She demanded to see my ticket, pointed out that it said “no carry-on”—which I acknowledged—and I reiterated that this was precisely why we paid to check our bags. Her response was, “I don’t make the rules.” She then walked away, but not before asking if I “truly wanted to fly back to Chicago today?”—an unnecessary and unmistakable threat. It is also worth noting that despite booking our tickets together in the same transaction, we were not seated together. Upon our return to Chicago—where we could once again sit together—we compared onboard experiences. We both remarked on how unhappy the flight attendants appeared and how each of us was separately asked whether we would like to purchase a beverage. We declined. At no point was water mentioned as an option, leaving us with the clear impression that even water came at a cost—or that complimentary water, if available at all, was deliberately left unmentioned. Overall, the experience was shocking and deeply disappointing, but it was also a profound learning experience—one we will not forget and will not repeat. -Steve

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

Everything you need to know for your flight from Denver to Seattle

Other airlines flying from Denver to Seattle

Flights from the other most popular airlines that fly from Denver to Seattle according to KAYAK users. Prices are the lowest found on KAYAK over the last 7 days. Price and availability are not guaranteed.