SFO Security: Checkpoints, Hours, PreCheck and Wait Times

SFO names each checkpoint by the letter of the nearest gates. Hours are the ones SFO publishes (checked October 10, 2026):

• Checkpoint A (International Terminal, A gates): 4:15 a.m. to 2:00 a.m.
• Checkpoint B, Departures Level (Harvey Milk Terminal 1, B and C gates): 3:15 a.m. to 12:30 a.m.
• Checkpoint B, Mezzanine Level (Harvey Milk Terminal 1): 4:00 a.m. to 11:00 p.m.
• Checkpoint D (Terminal 2, D gates): 3:15 a.m. to 12:30 a.m.
• Checkpoint F1 (Terminal 3, F gates): 3:15 a.m. to 12:30 a.m.
• Checkpoint G (International Terminal, G gates): 4:30 a.m. to 2:00 a.m.

You can use any checkpoint at any terminal if you have a valid boarding pass for the same day. Baggage carts aren't allowed through screening. Covenant Aviation Security, a private company under contract with the TSA, runs passenger and baggage screening at SFO.

The west side of Terminal 3 is being rebuilt, with new centralized checkpoint areas planned on the departures and mezzanine levels. What changes for you now:

• The Departures Level curb is closed between Doors 6 to 13. SFO suggests dropping off at Terminal 2 or the Terminal 3 arrival level. With no bags to check, drop off at Terminal 2 and go through the checkpoint.
• United check-in is split. For flights from the D and E gates, check in at the Terminal 2 counters. For flights from the F gates, use the Terminal 3 counters.
• The Terminal 3 AirTrain station is closed until the new facility opens in 2027. Use the combined Terminals 2 and 3 station.

Connecting from an international flight? SFO tells you to head to the checkpoint for your next gate: A gates, Terminal A checkpoint; B and C gates, Harvey Milk Terminal 1; F or G gates, International Terminal G; D gates, either the Terminal 3 F gates checkpoint or the AirTrain Red Line to the Terminal 2 D gates checkpoint.

SFO says every security checkpoint offers TSA PreCheck, Priority Line and CLEAR lanes. With PreCheck you keep your shoes, belt and light jacket on, leave your laptop in the bag and keep 3-1-1 liquids in your carry-on. SFO puts the average PreCheck wait at 5 minutes or less. That is an average, not a promise.

PreCheck Touchless ID (a face scan instead of showing your ID and boarding pass) is offered in Terminals 1, 2 and 3. You need an active PreCheck number, a passport uploaded to your airline profile, and an opt-in with Alaska, American, Delta, Southwest or United. Carry a REAL ID or other acceptable ID anyway, because a TSA officer can still ask for it.

Not enrolled yet? PreCheck costs $85 for five years, according to SFO's page. CLEAR Pods in all terminals can also handle PreCheck enrollment. The main enrollment spots are Terminal 2 (6 a.m. to 8 p.m. daily) and International A (7 a.m. to 8 p.m. daily), no appointment needed. Global Entry enrollment is by appointment only, with no walk-ins, in the International Terminal on the pre-security Arrivals Level (7:00 a.m. to 10:15 p.m. daily).

SFO says CLEAR offers expedited access to airport security lines in all of its terminals, using a biometric card, and that every checkpoint has a CLEAR lane. To become a member, visit clearme.com.

SFO shows live wait times for each checkpoint, general lanes and TSA PreCheck, on its Check In & Security page (flysfo.com/passengers/flight-info/check-in-security). The page notes that times change and that you can walk to any gate from any checkpoint, so check it before you pick a line. On the day we checked, SFO listed no PreCheck time for B Departure Level and no general time for B Mezzanine.

How early to arrive? SFO says the answer varies by airline and day, so check with your airline. The TSA encourages arriving two hours before a domestic flight and three hours before an international flight. Leave extra time for parking or transit and bag check. SFO's average PreCheck wait is 5 minutes or less. We found no SFO security reservation program.

Most international flights leave from the Dianne Feinstein International Terminal, with check-in on the Departures Level of the Main Hall. Air Canada is the exception: it uses Terminal 2 for check-in, boarding and baggage claim.

Arriving internationally? SFO is one of 38 U.S. airports with Mobile Passport Control express lanes in its Federal Inspection Area. The app lets eligible travelers submit their entry information ahead of a CBP officer check.

If you land from Canada or Ireland and are connecting, SFO says you stay in the secure area and follow signs to your gate, and checked bags go to your final destination. Everyone else clears customs, collects bags, follows the Connections sign, and goes through security again. United passengers can re-check bags in the re-check lobby.

SFO Gate Explorer lets non-flying guests go through security to reach gates, restaurants and the SFO Museum exhibits. Apply online up to 30 days ahead, or the same day. You'll get an approval email after 12:00 midnight on the day of your visit.

• Use a standard screening lane. Gate Explorer isn't accepted in PreCheck or CLEAR lanes.
• Bring a REAL ID or passport.
• Limit: one personal item.
• Ticketed passengers get priority, so you may wait a few minutes before joining the line.
• Meeting a Canada or Ireland flight is fine, because those passengers are treated as domestic on arrival.
• It can't be used to meet most international arrivals, because it doesn't give access to the customs area. Meet them on the Arrivals Level of the International Terminal instead.

All SFO boarding areas are connected after security, so once you pass any checkpoint you can reach the gates and amenities in any terminal. During Terminal 3 construction, interim post-security walkways link all the terminals around the work site, including one by Gate E2 that ends in the Terminal 3 food court and F gates area.