Connecting at San Francisco airport: terminals, customs and bag recheck

At San Francisco, all terminals are connected by walkways inside security, so once you've been screened you can walk to any gate. A domestic connection stays airside. Arriving from another country, you clear customs, recheck your bags at desks just outside the customs hall, and go through security once more before you continue.

How much time does the airport say you need?

SFO doesn't publish a minimum connection time. On one ticket, your airline sold you a connection that meets its minimum and must rebook you if you miss it. Read is a 1-hour layover enough?

Moving between terminals

• Walk inside security. The airport says all terminals are connected by walkways both before and after security.
• Airport train: runs 24 hours a day, as often as every four minutes; the full loop takes about nine minutes. Between 11 p.m. and 5 a.m. maintenance can slow it down.
• Terminal 3 train station: closed until a new station opens in 2027. Inside security you can walk to Terminal 3 instead.

Arriving from another country

The airport's steps:

1. Clear US Customs and Border Protection in the Federal Inspection Area.
2. Claim your bags after immigration, whatever your connection, and go through customs.
3. Exit through the doors marked "Connecting Flights".
4. Recheck your bags at the baggage desks just outside, if they're tagged to your final destination. If no agent is there, or your bags aren't tagged through, go to your airline's check-in counter.
5. Go through a security checkpoint, then walk to any gate.

Precleared flights get off directly into the secure area. Read international to domestic connections.

Customs wait times

From October 2025 to September 2026, passengers arriving from abroad at SFO waited 19 minutes on average to clear passport control, according to CBP: 14 minutes for US citizens and 25 minutes for visitors. 3.0% waited more than an hour. The slowest arrival hour was 9 a.m.–10 a.m., averaging 22 minutes. These times don't include collecting bags or walking to your next gate. See US customs wait times by airport.

On-time record

From September 2025 to August 2026, 65.4% of scheduled arrivals at San Francisco (SFO) reached the gate on time, rank 30 of the 30 busiest US airports. 74.0% of departures left on time and 1.0% of departures were canceled. The largest share of delay minutes came from the air traffic system (non-extreme weather, heavy traffic, air traffic control). See the full US airport on-time ranking.

Follow the first flight

Add both flights to FlyingOver before you travel. You'll follow the first flight offline and see its estimated arrival, and with Premium, connection guidance shows whether your layover looks comfortable, whether you need to keep moving or whether you should go directly to the gate.