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

Connect in the morning. The same one-hour layover misses 3% of the time at 9 am and 29% of the time at 4 pm.

Nonstops


United	SFO	BOS	5h 54m	80%	1.2%	1,904	Flying now
Delta	SFO	BOS	5h 40m	74%	1.5%	919	Flying now
JetBlue	SFO	BOS	5h 44m	74%	2.4%	1,736	Flying now
Alaska	SFO	BOS	5h 49m	81%	0.6%	173	Not flying now
Southwest	SFO	BOS	–	0%few flights	0.0%	1	Not flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Boston on time. Total trip = scheduled departure to arrival, layover included (Boston is 3 h ahead of San Francisco). Layovers up to 4 hours. Pick a connection for the details.


American Details →	SFO 22:05 → CLT 06:11AA 2514	2h 44m Charlotte	CLT 08:55 → BOS 11:08 +1AA 1533	10h 03m	98%	92%
United Details →	SFO 21:30 → IAD 05:53UA 357	2h 42m Dulles	IAD 08:35 → BOS 10:20 +1UA 641	9h 50m	100%	91%
Southwest Details →	SFO 23:40 → MDW 05:55WN 3649	3h 15m Chicago	MDW 09:10 → BOS 12:28 +1WN 1405	9h 48m	100%	90%
United Details →	SFO 16:10 → DEN 20:01UA 1430	3h 58m Denver	DEN 23:59 → BOS 05:58 +1UA 2656	10h 48m	100%	90%
United Details →	SFO 23:30 → ORD 05:57UA 368	1h 36m Chicago	ORD 07:33 → BOS 11:05 +1UA 1076	8h 35m	96%	89%
United Details →	SFO 19:45 → LAX 21:29UA 298	2h 30m Los Angeles	LAX 23:59 → BOS 08:40 +1UA 2210	9h 55m	100%	89%
American Details →	SFO 23:49 → CLT 08:05AA 1580	3h 13m Charlotte	CLT 11:18 → BOS 13:33 +1AA 1611	10h 44m	100%	89%
American Details →	SFO 23:08 → ORD 05:29AA 2554	3h 01m Chicago	ORD 08:30 → BOS 12:07 +1AA 4106 · flown by Envoy	9h 59m	99%	88%
Tight connection: often missed
Delta Details →	SFO 23:59 → ATL 07:42DL 690	53m Atlanta	ATL 08:35 → BOS 11:14 +1DL 2432	8h 15m	65%	59%
American Details →	SFO 23:49 → CLT 08:05AA 1580	50m Charlotte	CLT 08:55 → BOS 11:08 +1AA 1533	8h 19m	45%	43%
American Details →	SFO 12:18 → PHX 14:29AA 2548	46m Phoenix	PHX 15:15 → BOS 23:14AA 567	7h 56m	36%	25%

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

SLC · 1h 08m · leaves 05:50 3%

DEN · 1h 05m · leaves 05:00 3%

MSP · 1h 11m · leaves 06:00 4%

Afternoon and evening

DFW · 1h 05m · leaves 11:24 43%

LAX · 50m · leaves 18:43 47%

DEN · 55m · leaves 14:35 93%

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.


United UA 234 SFO 21:30 → DTW Delta DL 1163 DTW 07:05 → BOS Connection details →	1h 45m	8h 37m	100%	89%
United UA 1603 SFO 21:20 → ATL Delta DL 2432 ATL 08:35 → BOS Connection details →	3h 15m	10h 54m	98%	89%
United UA 368 SFO 23:30 → ORD American AA 4106 ORD 08:30 → BOS Connection details →	2h 33m	9h 37m	99%	89%

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