Frontier's Premium Bundle includes priority boarding and extra legroom seats.
Avoid Basic Fare to prevent extra fees for carry-on bags and seat selection.
Planning a trip from San Francisco to Denver? 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.
For those planning to fly from San Francisco to Denver, it's worth noting that Tuesdays and the month of September are generally the cheapest times to travel. Here are some tips to help you save money on this route:
Booking Advance: Try to book your flight at least 20 days in advance for the best prices.
Cheapest Airline: Frontier Airlines generally offers the cheapest flights on this route.
Direct Flights: Direct flights are significantly more expensive, so consider flights with layovers to save money.
Route Selection: The route from San Francisco to Denver is typically the cheapest.
Airline Selection: Consider flying with Frontier, as they generally offer the cheapest direct flights.
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 | October |
Cheapest flight | $26 |
Direct departures
San Francisco to Denver Intl
Monday
ANA, Air Canada, Air New Zealand, +8 more
ANA, Air Canada, +9 more
7
8
Tuesday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
Wednesday
ANA, Air Canada, Air China, +9 more
ANA, Air Canada, +10 more
8
9
Thursday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
Friday
ANA, Air Canada, Air New Zealand, +8 more
ANA, Air Canada, +9 more
7
8
Saturday
ANA, Air Canada, Air China, +8 more
ANA, Air Canada, +9 more
7
8
Sunday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
Direct returns
Denver Intl to San Francisco
Monday
ANA, Air Canada, Air New Zealand, +8 more
ANA, Air Canada, +9 more
7
8
Tuesday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
Wednesday
ANA, Air Canada, Air China, +9 more
ANA, Air Canada, +10 more
8
9
Thursday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
Friday
ANA, Air Canada, Air New Zealand, +8 more
ANA, Air Canada, +9 more
7
8
Saturday
ANA, Air Canada, Air China, +8 more
ANA, Air Canada, +9 more
7
8
Sunday
ANA, Air Canada, Air New Zealand, +7 more
ANA, Air Canada, +8 more
6
7
The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.
The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.
The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...
Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.
No trays in our seats, we sat in first row, purchased a business class fare. Had to hold our drinks and snack in our hands. No plugs for our cell phones. Had to pay for it a drink cocktail each. Seats so uncomfortable.
Flight wasn’t even full, but too many carry-ons caused us to run out of bin space. New bag fee has folks who would usually check their bags carrying on. Watching Southwest morph into Spirit/Frontier is so sad to watch
Flights delayed by 4-6 hours. Boarding was a mess and unclear. Bags were not at arrival airport and had never even been put on the plane. No idea when I’ll get them. Don’t fly into Denver!
Southwest is Southwest. No frills. If you're luck enough to get a happy crew (we did), then it makes for a nicer flight.
Southwest is typically delayed, and it gets wearisome. It is no longer a discount airline and you get way less than you pay for when it comes to comfort and Ce.
We sat on the plane on the tarmac for 4 hours.
After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!
Excellent flight. Boarding was efficient and departure was on time. Smooth flight with on time arrival. Deplaning was also efficient.
Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.
I never flew. Flight was canceled. DIA worst airport in the country. Avoid at all costs.
Very rough getting into denver. my kid threw up it was so rough.
Why wasn't this flight departure scheduled eith another crew so that it could leave on time? When we arrived in Denver we had so little time between flights we had run to the connecting flight. We should received some credit for the inconvenience.
I was supposed to be on business class at first class from Denver back to Miami due to weather changes. I missed my connection and it’s put on a flight to Fort Lauderdale. Instead of honoring my business class/1st class ticket, they put me in coach, but there were two first class seats open. I think it’s absolutely disgusting that I paid for first class $1300 ticket and they put me in economy and they had to open seats available and I have still not been refunded the difference. I ended up having to eat a snack box instead of the meal I was supposed to get and did not get home till 2 AM so I think that’s a little pathetic that I had to live off crackers for dinner And my poor dog ate some cheese and salami. Oh yes, apparently when they switched me to the new flight they forgot to mention I had a service dog
Excellent service despite turbulence during the flight. Flight attendants were remarkable!
Flight attendant moved my bag without notifying me and was rude to me when I asked him about it. There was no reason to move it.
Food choices were very limited. Taste of the dishes was average.
I liked all the informational texts. I always knew where to go and when .
4 hours late, including over +1 hour waiting in plane to take off. Baggage left behind too.
While waiting to claim my checked luggage, I discovered the airline had lost it. After a long wait and inquiries, I discovered it was on another flight. Fortunately, the airline finally sent my luggage home.
Was not able to watch most shows on the entertainment site. They would not load
Our flight was 1.5 hours delayed. There was no weather for the inbound flight, so I don't understand why. This meant a VERY late arrival and only a quick nap before my morning flight.
Delayed flight, so I switched fights to SFO to Phoenix , Phoenix to DSM. Excellent service through American Airlines
AA re-routed flight from HNL to LAX due to delay. My group of 3 with reserved seats in row 9 was broken up, with one assigned to a middle seat, another in the last row of the plane. Not happy. No explanation to the delay. No apologies. No compensation. Would have been nice to be offered an Admiral Club admission or a voucher for the extra 3 hours of layover in LAX. Could not hear the boarding gate announcements in LAX. Adjacent gate was boarding at the same time. Loud speakers were competing against each other. Barely made my boarding group.
Almost a 6 hour flight and the only food option is a cheese plate… and chips. Also how is it there are no options for texting on American. I’ll be going back to delta and united.
The chair cushions may need an upgrade. I have been noticing they are so worn out, thin so you’d sit in a dip 😄. Other than that, all was an enjoyable trip. Thanks AA!
Cramped seats. FAA should make airlines have more legroom, for even short people complain
Eventless. It was a good flight and good crew. Can’t complaint.
It was canceled. The flight wasn’t rescheduled, everyone had to figure out their own new arrangements. They said we would get refunded our original fare and receive an additional $150. We received links for $100 only and they expired before we could activate them.
The plane had originated in Las Vegas at 6:30 in the morning and flew to Moline where we boarded. The flight left around 12:30 PM and there were no boxed snacks available and many of the alcoholic beverages were unavailable. I would find it hard to believe that that many of the passengers coming from Las Vegas at 6:30 in the morning, drank and ate that much of the items. I can only come to the conclusion that someone failed to stock the plane for the round-trip. This is a huge revenue failure for the airline and disappointment for the passengers. The flight crew did not seem happy to be there and did not engage with passengers. Allegiant you can do better.
They did not let my husband on the plane with our service animal at the last minute. Do NOT fly this airline with a service animal!
Tight! Seats are not designed for those of us who wear extra-large clothes.
The non-stop flight from Grand Rapids was excellent. I neither expected or needed a budget flight and Allegiant made the trip easy and for an affordable price, Arriving at the Mesa Airport (AZA) is a delight compared to the international airport. For our return flight, we were able to arrive 75 minutes before the flight, return the rental car, check our bag and make it to the gate in plenty of time. That would never happen at most airports.
Easiest flights I’ve ever taken. Plane was comfortable without overly crowded seating.
Terrible. Still have not received the refund from them. They sent it to some account that I don't even know. Spoke with costumer service and they are unable to help.
I didn’t like it at all. I miss my second flight because of the delay on Allegiant Air now I m stuck in MCO.
Good, but a bit late on take off after loading. Don't like charging for carry ons!
First time flying with them and will definitely fly again in the future. Crew was so nice and friendly, fought was seamless. They are simple planes, no entertainment, but it’s fine for a short flight or if you have personal devices Rates are competitive, and they did so well with keeping the flight on time after a tropical storm, where other airlines had delays and cancellations.
As every law enforcement agency I could imagine surrounded the plane and we didn’t disembark for 2 hours and then had to stick around for another hour to go get our personal belongings after leaving them behind and being bused away from the plane, it was scary and inconvenient. We were given no information as to why this was happening. Lack of communication with passengers was disappointing.
Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.
Late, terrible communication, horrible planning of passenger seating until the literal last minute. One of the worst flying experiences of my life. Y'all suck
First of all, we never got on the connecting flight to Denver. They delayed our flight for two hours. If we would have gotten on that flight, we would have been stuck in Denver for 13 hours. So we re- routed our flight for a straight through flight to Oklahoma two days later. THEN, they delayed that flight for two hours. After that we were able to finally get on our flight and come home. Frontier Airlines - one of the worst airlines I have ever been on.
Terrible communication with weather delay, lost baggage, near impossible to reach customer service
My tickets got canceled on me by your site and I didn't have a flight. Then you kept sending me emails on the status of q flight I didn't have tickets for.
Flight was late. Missed connecting in Denver. My new flight is more than 24 hours later and I have no room, vouchers, or compensation, and might also be bumped from the one tomorrow.
This was one of the first frontier airline flights this spring that wasn't delayed. It actually left on time. Some of the flight crew did not look happy, they didn't smile when the passengers were boarding or getting off the plane, and the passengers initiated greetings, not the staff. To me this was an odd experience to have with any flight/airline. I had a bad experience booking this flight. The price didn't solidify until late hours into the night. Ever time I purchased the ticket, I either received a denial email or an error because the price has changed, but it was never reflected on the flyfrontier or kayak websites until way after midnight on the date of travel. This caused me anxiety and irritation with the websites. Then I noticed a mishap with my name on my voucher as I went to check in, it was incorrect. When I proceeded to correct it, Frontier had no easy, let alone free, way to remedy it. I couldn't correct my name without a $75 charge, I couldn't cancel my voucher to repurchase it with the correct name without a $100 charge, because it was too close to departure. Then calling frontier was nearly impossible to remedy the situation with a human. It's already difficult to want to choose frontier because of all the upcharges, but you feel kinda trapped into doing so because it's the more affordable airline.
Our flight was cancelled. They could do nothing to help us get another flight that was timely. Because the first leg was cancelled we were unable to get to our connection. We had to book on an entirely different airline for today. So we spent more money, lost a day of vacation and will never fly Frontier again, so the 'we are sorry, here is $100 credit' is a joke since we won't be flying on Frontier.
I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.
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