Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: airlines and hours on this route all land within a few points of 63% on time.

Nonstops


Delta	SEA	SFO	2h 21m	67%	1.4%	1,747	Flying now
United	SEA	SFO	2h 18m	65%	0.8%	2,327	Flying now
Alaska	SEA	SFO	2h 16m	59%	1.2%	2,718	Flying now
Southwest	SEA	SFO	–	100%few flights	0.0%	4	Not flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach San Francisco on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


Alaska Details →	SEA 11:23 → GEG 12:29AS 449	3h 52m Spokane	GEG 16:21 → SFO 18:45AS 3070 · flown by SkyWest	7h 22m	98%	85%
Alaska Details →	SEA 07:26 → SAN 10:23AS 1471	3h 07m San Diego	SAN 13:30 → SFO 15:14AS 3352 · flown by SkyWest	7h 48m	100%	74%
Alaska Details →	SEA 10:14 → PDX 11:21AS 3090 · flown by SkyWest	3h 28m Portland	PDX 14:49 → SFO 16:40AS 236	6h 26m	100%	72%
Alaska Details →	SEA 08:11 → JAC 11:20AS 3362 · flown by SkyWest	1h 51m Jackson	JAC 13:11 → SFO 14:49AS 3208 · flown by SkyWest	6h 38m	96%	71%
Delta Details →	SEA 12:35 → LAX 15:26DL 2914	2h 09m Los Angeles	LAX 17:35 → SFO 18:55DL 1559	6h 21m	98%	66%
Delta Details →	SEA 07:15 → LAX 10:05DL 1628	1h 55m Los Angeles	LAX 12:00 → SFO 13:26DL 2725	6h 13m	98%	66%
Delta Details →	SEA 05:30 → SLC 08:30DL 1128	2h 30m Salt Lake City	SLC 11:00 → SFO 12:08DL 902	6h 38m	98%	64%
Delta Details →	SEA 09:30 → SLC 12:38DL 1016	2h 32m Salt Lake City	SLC 15:10 → SFO 16:12DL 1088	6h 45m	99%	64%
Tight connection: often missed
Alaska Details →	SEA 14:22 → GEG 15:25AS 2074 · flown by Horizon	56m Spokane	GEG 16:21 → SFO 18:45AS 3070 · flown by SkyWest	4h 23m	75%	63%
Alaska Details →	SEA 08:45 → PDX 09:49AS 3132 · flown by SkyWest	53m Portland	PDX 10:42 → SFO 12:39AS 1445	3h 54m	71%	38%
Alaska Details →	SEA 15:59 → LAX 18:44AS 1300	50m Los Angeles	LAX 19:34 → SFO 20:57AS 1601	4h 58m	63%	9%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

DEN · 1h 00m · leaves 05:00 4%

BOI · 1h 12m · leaves 07:07 5%

SNA · 1h 16m · leaves 06:40 5%

Afternoon and evening

SAN · 1h 14m · leaves 14:23 15%

GEG · 56m · leaves 14:22 25%

LAX · 50m · leaves 15:59 37%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.


Frontier F9 1178 SEA 11:03 → LAX United UA 233 LAX 17:10 → SFO Connection details →	3h 09m	7h 35m	98%	80%
United UA 1730 SEA 17:04 → LAX American AA 6510 LAX 22:32 → SFO Connection details →	2h 39m	6h 55m	94%	76%
Alaska AS 467 SEA 10:03 → SAN United UA 2117 SAN 16:09 → SFO Connection details →	3h 08m	7h 46m	100%	75%

Rank all connections, any airlines →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON