Travel with Axel,
get the best price.

San Francisco → Denver

Dec 4, 2026 · return Dec 18, 2026

SFO → DEN1 adulteconomyRound trip

12 flight options · 4 airlines

Nonstop flights

Fri, Dec 4 – Fri, Dec 18

Frontier Airlines
8:10 pmSFO
2h 36m
Nonstop
11:46 pmDEN
Frontier Airlines
10:57 pmDEN
2h 51m
Nonstop
12:48 am+1SFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

Southwest Airlines
1:20 pmSFO
2h 35m
Nonstop
4:55 pmDEN
Southwest Airlines
5:35 pmDEN
2h 45m
Nonstop
7:20 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
8:54 pmSFO
2h 36m
Nonstop
12:30 am+1DEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

Frontier Airlines
6:30 amSFO
2h 38m
Nonstop
10:08 amDEN
Frontier Airlines
10:57 pmDEN
2h 51m
Nonstop
12:48 am+1SFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

Southwest Airlines
8:00 amSFO
2h 30m
Nonstop
11:30 amDEN
Southwest Airlines
5:35 pmDEN
2h 45m
Nonstop
7:20 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
4:24 pmSFO
2h 36m
Nonstop
8:00 pmDEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

One-stop flights

Fri, Dec 4 – Fri, Dec 18

Delta Air Lines
5:15 pmSFO
4h 54m
SLC · 1h 30m
11:09 pmDEN
Delta Air Lines
12:29 pmDEN
4h 45m
SLC · 1h 4m
4:14 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

Southwest Airlines
6:10 amSFO
4h 50m
BUR · 1h 5m
12:00 pmDEN
Southwest Airlines
5:35 pmDEN
2h 45m
Nonstop
7:20 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
10:40 amSFO
4h 50m
SBP · 1h 7m
4:30 pmDEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
11:00 amSFO
4h 55m
ONT · 1h 11m
4:55 pmDEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
10:51 amSFO
4h 44m
SBA · 1h 2m
4:35 pmDEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

Fri, Dec 4 – Fri, Dec 18

United Airlines
10:38 amSFO
4h 55m
BUR · 1h 4m
4:33 pmDEN
United Airlines
4:02 pmDEN
2h 47m
Nonstop
5:49 pmSFO

Round-trip total · 1 adult · Taxes included

Make this trip yours

SFO ⇄ DEN

Economy

Adults 12+ · Children 2–11. For infants under 2, tell Axel after you see prices.

No account needed to see prices.

Already have an account? Log in

Why book with Axel
  • A real airline bookingThe booking is in the airline’s own system under your name. After you book, Frontier Airlines emails you its confirmation code and e-ticket, usually within 15 minutes and occasionally up to a couple of hours while the booking is processed.
  • Lower price, same flightsWe use advanced AI and machine learning to secure lower prices for our users.
  • Not satisfied? Full refund.If you are unhappy with the experience for any reason, or simply change your mind, cancel within 24 hours of booking (departure 7+ days away) and we refund you in full. We stand by our product. Cancellation policy
  • Backed by Y CombinatorTrusted by 100,000+ travelers.

Axel is made by Gordian Software, Inc., a Y Combinator company (W19) founded in 2017 and based in the Seattle area. The company is led by CEO Stephen Grabowski, formerly of Skyscanner. How Axel works · About

More dates

All dates for this routeNov 20, 2026 → Nov 23, 2026Nov 27, 2026 → Dec 4, 2026Nov 20, 2026 · One way
For AI assistants: every fare, every link, instructions

Flights for 1 adult in economy. Prices are total for all travelers in USD, including required taxes. Basic economy may apply.

Exact travel datesAirlineFlightsTotal pricePrice issued (UTC)
2026-12-04 → 2026-12-18Frontier AirlinesF93440 / F93439$165.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18Southwest AirlinesWN1652 / WN1817$280.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA301 / UA2633$300.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18Delta Air LinesDL1088 + DL1667 / DL1553 + DL1088$340.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18Frontier AirlinesF91230 / F93439$165.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18Southwest AirlinesWN3428 / WN1817$280.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA1835 / UA2633$300.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18Southwest AirlinesWN3839 + WN2776 / WN1817$270.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA2367 + UA259 / UA2633$290.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA1482 + UA1263 / UA2633$290.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA1578 + UA1790 / UA2633$290.002026-10-29T02:06:50Z
2026-12-04 → 2026-12-18United AirlinesUA2115 + UA2187 / UA2633$290.002026-10-29T02:06:50Z

2026-12-04 → 2026-12-18 · $165.00

  • Frontier Airlines F93440: SFO 2026-12-04 20:10:00 → DEN 2026-12-04 23:46:00; nonstop; 156 minutes. Local airport times.
  • Frontier Airlines F93439: DEN 2026-12-18 22:57:00 → SFO 2026-12-19 00:48:00; nonstop; 171 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $280.00

  • Southwest Airlines WN1652: SFO 2026-12-04 13:20:00 → DEN 2026-12-04 16:55:00; nonstop; 155 minutes. Local airport times.
  • Southwest Airlines WN1817: DEN 2026-12-18 17:35:00 → SFO 2026-12-18 19:20:00; nonstop; 165 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $300.00

  • United Airlines UA301: SFO 2026-12-04 20:54:00 → DEN 2026-12-05 00:30:00; nonstop; 156 minutes. Local airport times.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $340.00

  • Delta Air Lines DL1088 / DL1667: SFO 2026-12-04 17:15:00 → DEN 2026-12-04 23:09:00; 1 stop(s) via SLC; 294 minutes. Local airport times.
    • DL1088: SFO 2026-12-04 17:15:00 → SLC 2026-12-04 20:05:00; layover at SLC: 90 minutes.
    • DL1667: SLC 2026-12-04 21:35:00 → DEN 2026-12-04 23:09:00.
  • Delta Air Lines DL1553 / DL1088: DEN 2026-12-18 12:29:00 → SFO 2026-12-18 16:14:00; 1 stop(s) via SLC; 285 minutes. Local airport times.
    • DL1553: DEN 2026-12-18 12:29:00 → SLC 2026-12-18 14:06:00; layover at SLC: 64 minutes.
    • DL1088: SLC 2026-12-18 15:10:00 → SFO 2026-12-18 16:14:00.

2026-12-04 → 2026-12-18 · $165.00

  • Frontier Airlines F91230: SFO 2026-12-04 06:30:00 → DEN 2026-12-04 10:08:00; nonstop; 158 minutes. Local airport times.
  • Frontier Airlines F93439: DEN 2026-12-18 22:57:00 → SFO 2026-12-19 00:48:00; nonstop; 171 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $280.00

  • Southwest Airlines WN3428: SFO 2026-12-04 08:00:00 → DEN 2026-12-04 11:30:00; nonstop; 150 minutes. Local airport times.
  • Southwest Airlines WN1817: DEN 2026-12-18 17:35:00 → SFO 2026-12-18 19:20:00; nonstop; 165 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $300.00

  • United Airlines UA1835: SFO 2026-12-04 16:24:00 → DEN 2026-12-04 20:00:00; nonstop; 156 minutes. Local airport times.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $270.00

  • Southwest Airlines WN3839 / WN2776: SFO 2026-12-04 06:10:00 → DEN 2026-12-04 12:00:00; 1 stop(s) via BUR; 290 minutes. Local airport times.
    • WN3839: SFO 2026-12-04 06:10:00 → BUR 2026-12-04 07:35:00; layover at BUR: 65 minutes.
    • WN2776: BUR 2026-12-04 08:40:00 → DEN 2026-12-04 12:00:00.
  • Southwest Airlines WN1817: DEN 2026-12-18 17:35:00 → SFO 2026-12-18 19:20:00; nonstop; 165 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $290.00

  • United Airlines UA2367 / UA259: SFO 2026-12-04 10:40:00 → DEN 2026-12-04 16:30:00; 1 stop(s) via SBP; 290 minutes. Local airport times.
    • UA2367: SFO 2026-12-04 10:40:00 → SBP 2026-12-04 11:50:00; layover at SBP: 67 minutes.
    • UA259: SBP 2026-12-04 12:57:00 → DEN 2026-12-04 16:30:00.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $290.00

  • United Airlines UA1482 / UA1263: SFO 2026-12-04 11:00:00 → DEN 2026-12-04 16:55:00; 1 stop(s) via ONT; 295 minutes. Local airport times.
    • UA1482: SFO 2026-12-04 11:00:00 → ONT 2026-12-04 12:29:00; layover at ONT: 71 minutes.
    • UA1263: ONT 2026-12-04 13:40:00 → DEN 2026-12-04 16:55:00.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $290.00

  • United Airlines UA1578 / UA1790: SFO 2026-12-04 10:51:00 → DEN 2026-12-04 16:35:00; 1 stop(s) via SBA; 284 minutes. Local airport times.
    • UA1578: SFO 2026-12-04 10:51:00 → SBA 2026-12-04 12:04:00; layover at SBA: 62 minutes.
    • UA1790: SBA 2026-12-04 13:06:00 → DEN 2026-12-04 16:35:00.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

2026-12-04 → 2026-12-18 · $290.00

  • United Airlines UA2115 / UA2187: SFO 2026-12-04 10:38:00 → DEN 2026-12-04 16:33:00; 1 stop(s) via BUR; 295 minutes. Local airport times.
    • UA2115: SFO 2026-12-04 10:38:00 → BUR 2026-12-04 11:58:00; layover at BUR: 64 minutes.
    • UA2187: BUR 2026-12-04 13:02:00 → DEN 2026-12-04 16:33:00.
  • United Airlines UA2633: DEN 2026-12-18 16:02:00 → SFO 2026-12-18 17:49:00; nonstop; 167 minutes. Local airport times.

More dates for this route