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


United	ONT	SFO	1h 27m	67%	0.5%	1,113	Flying now
Frontier	ONT	SFO	1h 37m	39%	2.6%	196	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.


United Details →	ONT 05:00 → DEN 08:20UA 2446	3h 01m Denver	DEN 11:21 → SFO 13:04UA 1561	8h 04m	99%	71%
Alaska Details →	ONT 10:54 → PDX 13:09AS 1699	1h 40m Portland	PDX 14:49 → SFO 16:40AS 236	5h 46m	98%	70%
Alaska Details →	ONT 06:02 → SEA 08:44AS 607	2h 58m Seattle	SEA 11:42 → SFO 14:04AS 655	8h 02m	100%	69%
Alaska Details →	ONT 12:04 → SEA 14:44AS 654	1h 52m Seattle	SEA 16:36 → SFO 18:48AS 1385	6h 44m	98%	66%
Delta Details →	ONT 06:00 → SLC 08:50DL 2708	2h 10m Salt Lake City	SLC 11:00 → SFO 12:08DL 902	6h 08m	98%	64%
Delta Details →	ONT 09:40 → SLC 12:28DL 1302	2h 42m Salt Lake City	SLC 15:10 → SFO 16:12DL 1088	6h 35m	100%	64%
Delta Details →	ONT 17:21 → SLC 20:17DL 4443 · flown by SkyWest	2h 33m Salt Lake City	SLC 22:50 → SFO 23:52DL 1091	6h 35m	96%	64%
Alaska Details →	ONT 17:32 → PDX 19:49AS 2456 · flown by Horizon	1h 56m Portland	PDX 21:45 → SFO 23:36AS 2112 · flown by Horizon	6h 04m	98%	61%
Tight connection: often missed
Frontier Details →	ONT 15:34 → LAS 16:46F9 4758	1h 05m Las Vegas	LAS 17:51 → SFO 19:44F9 3801	4h 10m	73%	45%
Southwest Details →	ONT 20:42 → PHX 21:58WN 3160	52m Phoenix	PHX 22:50 → SFO 00:55 +1WN 1098	4h 13m	36%	21%
Alaska Details →	ONT 14:05 → SEA 16:45AS 567	51m Seattle	SEA 17:36 → SFO 19:52AS 791	5h 47m	68%	18%

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.

Afternoon and evening

LAS · 1h 05m · leaves 15:34 27%

SEA · 51m · leaves 14:05 32%

PHX · 52m · leaves 20:42 64%

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.


Southwest WN 3145 ONT 08:05 → DEN United UA 1812 DEN 13:25 → SFO Connection details →	2h 10m	7h 04m	96%	73%
Southwest WN 3144 ONT 05:50 → DEN United UA 1561 DEN 11:21 → SFO Connection details →	2h 16m	7h 14m	100%	72%
Delta DL 3816 ONT 06:20 → SEA Alaska AS 655 SEA 11:42 → SFO Connection details →	2h 25m	7h 44m	95%	66%

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