United’s Economy Plus seats offer up to 6 inches more legroom than standard economy.
United offers Priority Boarding for Zone 2, reducing overhead bin space worries.

Planning a trip from Denver to Boston? 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 Boston, there are several strategies to consider for saving money. Generally, Wednesday is the cheapest day of the week to fly, and January is the cheapest month.
Advance Booking: Book your flight at least 57 days in advance for the best prices.
Cheapest Airline: Consider flying with Frontier, as it is generally the cheapest airline for this route.
Direct Flight: Opt for a direct flight, as it is significantly cheaper than flights with layovers.
Specific Route: Stick to the direct route from Denver International to Boston Logan International for the best deal.
Off-Peak Travel: Consider traveling in January for the lowest monthly rates.
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 | February | 
|---|---|
| High season | July | 
| Cheapest flight | $96 | 
Direct departures
Denver Intl to Boston Logan Intl
Monday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Tuesday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Wednesday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Thursday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Friday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Saturday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Sunday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Direct returns
Boston Logan Intl to Denver Intl
Monday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Tuesday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Wednesday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Thursday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Friday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Saturday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Sunday
Delta, JetBlue, Southwest, +1 more
Delta, JetBlue, +2 more
1
Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.
Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.
Full cans of soda would be nice. A choice between two snacks would be appreciated.
Tried watching free movie and it kept freezing so I couldn’t finish.
All was good. I just had a hard time getting connected to the WiFi/internet during the flight
Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.
Great flight. Outstanding Service. Southwest was able to put us on a direct flight to Denver when the connection could have been affected by a later arrival to Baltimore. The direct flight was less expensive that the flight with the connection in Baltimore.
Delays delays delays. Late taking off, late landing, wait for a gate, etc.
Boarded on time but once we were ready for take off, the crew determined that, although every seat was taken, somehow someone was on the wrong flight. Delay, delay delay, announcements and ended up with one person checking EVERY ID against their passenger Manifest only to figure out it was a "clerical error." We departed 54 minutes late causing me to run in the St. Louis Airport to make my connection and lose the priority boarding spot I had paid for. Unnecessary delay.
I was re-booked onto another flight because my original flight was delayed and I would have missed my connector. I ended up in the “C” group after paying extra to be in the “A “ group on the original flight. At least if you’re going to re-book people, re-book them into the same group.
Flight was delayed due to plane not passing inspection And one of the crew had to time out and we had to wait for another one A 3 hour delay
Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.
They ended up paying for the bag twice, but the counter wouldn't take my baggage receipt. Left it to me to resolve. Not sure how to resolve the issue.
The customer service before board was very rude and when I expressed my concerns about making the connecting flight she laughed and told me I bought the wrong ticket. I explained once it showed the flight was delayed it no longer let me change seats or anything. I was trying to upgrade to make sure I would get to the next gate on time.
Non stop on long haul is the way to go. Great experience
The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.
They changed planes and the new plane couldn’t carry enough fuel to fly across the country so we had to stop in Kansas City to refuel. Flight was delayed .
Flight was too crowded and seats are too small, especially since passengrs are getting larger. Having a middle seat is ALWAYS tough! Woman on my left was large & kept creeping in to my space. Flight personnel were great! Have more savory rather than sweet snacks please.
Flight was crowded and the woman sitting on my left was large & kept crouching in to my space. You need bigger seats or smaller passengers to fit into the seats you DO have! Snack were OK. Would appreciate if airlines had more savory rather than sweet snacks, thank you!
Delayed flight (1hour) plus a long layover after an overnight flight with no backup plane available.
We were delayed, which I think had to do with air traffic control. Otherwise, everything was great.
Crew seemed a bit cranky. No seatback screens. But boarding was efficient and on time and we arrived early.
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
Plenty of room for me and the cat in Premium Economy. Seat was comfortable. Boarding was a breeze. The lady at the special check-in desk was great, super helpful and professional.
It’s been awhile since I have traveled on United. I, along with my family who were on the flight noted how smoothly everything went . Boarding, flight crew and service was excellent.
The flight was two hours late due to a computer fault and resulting maintenance. Nothing was offered as compensation beyond bottles of water during the time we were deplaned and waiting in the terminal.
Very pleasant flight attendants. Gate crew rather loud chatting with each other.
Four plus hour flight delay in New York caused us to take off after 11:30pm. We didn’t arrive at our hotel until five hours after check in. Started the trip off feeling exhausted.
Friendly crew. Poor food service maybe due to full flight. All in all, you get what you pay for.
Plane was in bad shape. TV’s and WiFi didn’t work. Plane need a refresh. Not enough room for bags.
Everything was great. I liked the text updates so that I never miss a gate change & I have all the latest info.
I don’t usually fly budget airlines or airlines in the United States. It was as good as any other airline. The seats are comfortable and the airline attendants are not rude & surly. Very nice flight (s).
They have the most inexperienced / rude flight staff I’ve encountered
very difficult boarding process - aggressive passengers not the friendliest crew
WiFi was not eorkig (again) And the plane was from 1990 with the screens which were.not touch and most didn’t even work and if lucky could tune in tv
Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.
Boarding was on time and plane departed as scheduled. There are obviously no amenities (food, drink, entertainment) on Frontier, but there also didn't seem to be any issues with luggage space either.
Inbound plane was on time and flight departed on time with no issues while boarding.
I knew going into this that Frontier, being a low cost carrier, would be pretty bare bones and charge for most extras but this was made up for by the fact that the airplane was a reasonably new Airbus, every employee was great and best of all, Everett Washington is an amazing airport - thanks Frontier for flying there!!!
i was unable to check in the flight. refund requested
It was well done. It was my first time flying with them and I was nervous b/c I have heard of many cancelled and/or delray flights. Everything went smoothly.
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.
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
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