Frontier's Premium seats provide up to seven inches more legroom than Standard seats.
Avoid Basic Fare to select your seat and ensure carry-on space.

Planning a trip from Denver to Portland? 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.
When planning a flight from Denver to Portland, there are several strategies that could potentially save you money. Generally, the cheapest day of the week to fly is Saturday, and the cheapest month to fly is February.
Day Selection: Opt to fly on Saturdays for the lowest fares.
Month Selection: Consider flying in February to save on airfare.
Booking Advance: Book your flight at least 15 days in advance to get the best deal.
Airline Choice: Frontier Airlines generally offers the cheapest flights for this route.
Flight Type: Direct flights are typically more expensive, so consider flights with layovers to save money.
AI-powered; AI can make mistakes.
| Low season | February |
|---|---|
| High season | July |
| Cheapest flight | $49 |
Direct departures
Denver Intl to Portland
Monday
Alaska Airlines, Southwest, United Airlines
Alaska Airlines, Southwest, +1 more
Tuesday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Wednesday
Alaska Airlines, Southwest, United Airlines
Alaska Airlines, Southwest, +1 more
Thursday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Friday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Saturday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Sunday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Direct returns
Portland to Denver Intl
Monday
Alaska Airlines, Southwest, United Airlines
Alaska Airlines, Southwest, +1 more
Tuesday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Wednesday
Alaska Airlines, Southwest, United Airlines
Alaska Airlines, Southwest, +1 more
Thursday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Friday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Saturday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Sunday
Alaska Airlines, Frontier, Southwest, +1 more
Alaska Airlines, Frontier, +2 more
1
Food was bad. Just a drink for a 5 hour flight
Food was bad. Just a drink for a 5 hour flight
I liked that the crew was friendly, we left and arrived at near scheduled times, plenty of on-board crew to handle the cabin service for the flight and I found the price of my airline ticket to be excellent!
No accommodation or credit offered for cancelled layover flight to Eugene from portland
If they actually let me fly. I was rerouted to United and there was no Alaska airlines reps at all. Then the lady who worked the delta counter told me to go away and figure things out myself. Horrible experience.
Late. Too long a flight for a 737. 0.5 oz of pretzels for a 5+ hour flight at dinner time. One step above Ryan Air/ several below Delta.
Once again, Hawaiian Airlines upon checking in for our return flight, told us that we hadn’t paid for our extra comfort seats. This had happened on our incoming flight as well. Hawaiian Airlines had changed our flight and put us in standard seats. I sent them confirmation emails and receipts showing that I had paid for extra comfort seats and they ignored me and refused to accept my proof of payment. I ended up having to pay for our extra comfort seats again. On our return flight, once again, we were told we hadn’t paid for our extra comfort seats, which we had. I argued until a supervisor was summoned and researched further in their system and found that we had paid for them. If I hadn’t insisted, we would’ve been forced to buy our seats again or be assigned a standard seat. This kind of Customer Service is totally unacceptable. I would never use Hawaiian Airlines again if I have a choice.
Flight delay caused me to miss my connecting flight home, but I was put up at a nearby motel, and it was great
My seat. The reprentative on the phone was bad. The passengers screamed at each other and no one stopped them. The directions boarding the plane were unclear. There was a medical incident and the ICU nurse present said the women was having a cardic incident. Cooler heads determined it was a UTI. I had a allergy attack and a guy got a mask from the flight attendent and told me to wear it. He "had kidney failure". Why didnt they tell him to wear the mask, why was he even on the plane? It was embarrassing, he said hurtful things. By the way, I have a degree in Medical Micrbiology from Northwestern Medical school. MT(ASCP). Look it up. I Know the difference between allergies and an infection. But we had to listen to the unstable screaming man.
Wouldve liked a meal option (that you didnt have to prepay for) for such a long flight. But otherwise staff was friendly and boarding/un boarding was as efficient as it could be
The flight attendants were friendly. I liked that I got a mini soda can, not just a small cup. No issues with our flight departure, etc.
The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.
The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.
Still a fan of open seating. Flight was on schedule and arrived on time. The 737 MAX is very comfortable.
Airline travel is always too cramped to really be pleasant, but the cabin crew on this flight did a pretty good job of making up for it by putting on some music during boarding and sprinkling a few funny remarks into the safety briefing and announcements, and just generally being friendly and helpful. It definitely reminded me of why I prefer the in-flight experience on Southwest!
No delays and arrived to destination 30 min early. Staff was super friendly.
San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.
It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.
Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight
Had to get off plane from prior flight even though I had to reboard same plane to continue to my final destination.
Everything a cheap airline should be at normal airline rates.
Unfortunately, I was put into the middle seat in the first row of premium seating. Sounds nice right? No! that is the worst seat in the plane. I wish I was in economy rather than be in that seat! There is no seat back pocket, no tray table, no charger. Nothing! so unless you're row mates are willing to let you share their basic amenities any flyer should have, you are stuck. It was the worst experience ever! And the flight attendant forgot to take my drink order. I felt like the forgotten flyer.
Alaska was fine as usual. My frustration came with accessing boarding passes. On the first trip, I could only get one to print ans took a picture of the second one. On our return trip, the system was down? Friends who booked directly with Alaska had theirs process. I even tried the 800 number and had others try it too. It said something in Spanish and hung up. The agent at the airport succeeded.
Delayed and cancelled flights were hard and very stressful, both ways!
The crew was quite good, they came by often with drinks or to collect trash. But what wasn't nice was the flight was over weigh and several people had to be rebooked. I was questioned whether I should have a seat when I was getting to it. The in-flight entertainment kept buffering and interrupting. And the route took the airplane through high winds which caused us a longer flight
Wasn’t on the flight due to Alaska cancellation…also after all the rerouting, I was going to be on a later flight that left SFO at 7:47pm, which meant an almost 6 hour layover. That same Hawaiian flight was delayed for another 2hours.
I had to cancel the flight because with a 3 hour delay for 'unexpected maintenance' in getting to LAX, I couldn't connect to an overseas flight that I had booked on Scandinavian Air.
The flight was CANCELED!!! Can’t get much more “poor” than that. I had to switch to American Airlines, add another layover and got home in Honolulu 4 hours later than I was supposed to be home. One bright spot was Josh with Alaska Airlines at SFO. He got me on a United Flight that got me home a few hours before I would have. Without him I would have gotten home almost 7 hours after my originally scheduled flight.
Canceled my flight within 24 hours, causing me arriving home midnight. Will never book Hawaiian airlines anymore
I like Hawaiian, it was great that they had good internet connection across the Pacific Ocean, thanks to Star Link satellites. The seating was comfortable, ( I was in economy ). Maybe I missed it, but I only got offered a beverage once. It was a nonstop flight KOA to SMF. I would take it again next time I go that way.
I always love flying Hawaii and I have nothing to add
Crew seemed a bit cranky. No seatback screens. But boarding was efficient and on time and we arrived early.
I will never book a flight through Cheap fare. They booked me from Portland Main . And would not give me a refund, so I bought 2 tickets one for 299. From Portland Main to ORD. Then I had to buy a ticket from Oregon PDX to ORD that was another 440. So Just so you know they even told me it was there fault but no refund. Bad bussniess. I did inform United but they said they couldn't help me due to the fact I booked through Cheap Tickets. Never again. And I'm spreding the word. I let everyone know at my 50th class reunion
See previous note about the passenger in Denver who threw my husband's bag out of the overhead bin in order to maker room for his own. And the flight attendant back up the new passenger.
Terrible. They wouldn't allow me on my flight on the 14th..
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.
The gate attendant let me walk right by her with a bag too big for the overhead compartment
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.
Not clean and was told I would get a great seat and it was not great at all
Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.
Frontier is the Walmart of airlines. Frontier has removed adjustability and comfort from their seats to make the flight lighter and save gas. This makes it impossible to sleep on their flights. Their customer service is abysmal. Once, I bought a drink on the plane, and they swiped my credit card on the plane to pay for it. Then I got three weeks of daily notices from my bank telling me they tried to charge the wrong card number over and over again. I tried to call them, but they removed the ability to actually talk to someone that can resolve such a problem from their company to cut corners. The only way to talk to someone in person is to go to the check-in counter at the airport (40 minutes drive from my house). Eventually their system gave up on trying to charge the card, after 21 days of repeated tries. They don't pad their prices even a little to handle customer service issues like missed flights. They also have a blanket policy preventing helping you reschedule a missed flight if their system says you "cancelled" your own flight online. This is a major problem because their website is broken on mobile devices, the only web browser you have at the airport when their gate staff tell you that you have to reschedule your own missed flight online because they can't help you. I tried to reschedule my flight on my android device and instead, their website crashed and "cancelled" my missed flight. When I got to the counter, the agent argued with me for 5 minutes insisting that I intentionally cancelled my own flight (implying I had to buy another flight). She missed the point: the problem was that I could not buy another flight because their website is broken. I left to avoid more conflict with the "customer service" agent. I tried to redress my issue with their only other "customer service" chanel available: the contact form on their website. The response I got was more of the same: you cancelled your own flight, according to our website / computer records, therefore we won't help you. I was trying to explain the problem with their broken website that cost me hundreds of dollars by crashing / malfunctioning and resulting in a cancelled flight, but they only had deaf ears for this problem. Worst customer service I have ever experienced. I will never buy another Frontier flight again, because it is a risky, painful move that I will likely regret often.
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.
The delay was ridiculous because nary a word escaped from the gate attendant regarding our flight status. It was a complete joke.
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.