The earliest time you can go through airport security is 2-4 hours before the flight if you have checked baggage or as soon as the security checkpoints open on the same day. But this depends on which airport and airline you’re flying with and if you have checked bags.
If You Have Checked Bags, You Can’t Go Through Airport Security Very Early
In airports that don’t have luggage drop-off desks, you’ll have to wait until the check-in desks are open to drop off your checked bags. This usually happens 2-3 hours before domestic flights and 3-4 hours before international ones.
Larger airports sometimes have manned or self-service baggage drop-off desks. In these, you’ll most likely be able to drop off your checked bag earlier, as long as it’s on the same day of your flight. But not always.
You Can Go Through Airport Security Earlier if You Don’t Have Any Checked Bags
The general rule of thumb is that if your flight is on the same day, you’ll be allowed to go through security. Unfortunately, almost no airports allow going through security on the previous day. So if you want to check in very early, you’re limited only by the time when the security desks open. They usually open between 3-5 am or 2 hours before the first flight.
If you want to go through security very early, you should travel only with a carry-on and a personal item. In this case, you don’t need to wait until the check-in desks/luggage drop-off points open. Instead, you can go straight to security.
Airport Security Rules for Popular Airports
London Heathrow Airport
- Opens – 4:30am-05:00am
- Checked bags – 2 hours before flight
London Gatwick Airport
- Opens – 3 am
- Checked bags – 2 hours before flight
Los Angeles International Airport (LAX)
- Opens – 3am-4am
- Checked bags – 2 to 4 hours before flight
Ronald Reagan Washington National Airport
- Opens – 4:30am
- Checked bags – 2 to 5 hours before flight
John F. Kennedy International Airport (JFK)
- Opens – 4am-4:30am
- Checked bags – 2 to 4 hours before flight
Seattle-Tacoma International Airport
- Opens – 4am
- Checked bags – 2 to 4 hours before flight
San Francisco International Airport (SFO)
- Opens -3:30am-4:30am
- Checked bags – 3 to 4 hours before flight
Manchester Airport
- Opens – 4am-4:30am
- Checked bags – 2 to 4 hours before flight
London Stansted Airport
- Opens – 3am
- Checked bags – 2 to 4 hours before flight
Toronto Pearson Airport
- Opens – 3am
- Checked bags – 3 to 4 hours before flight
Dallas Fort Worth International Airport
- Opens – 5am
- Checked bags – 3 to 4 hours before flight
Vancouver International Airport (YVR)
- Opens – 4am-4:30am
- Checked bags – 2 to 4 hours before flight
Dublin Airport
- Opens – 4am
- Checked bags – 3 to 4 hours before flight
If You’re Transferring, You Don’t Need to Go Through Airport Security Again
If you have a connecting flight, even if it consists of two flights bought separately, you can stay in the airside area of the airport. After landing, there will be signs to “exit” and to “transfers”. If you go to the “transfers” area, you’ll enter the duty-free area of the airport and you won’t need to go through security again.
For Early Flights, You’re Allowed to Sleep in the Landside Area of the Airport
Most airports keep the Landside area of the airport open during the night. This is the area of the airport that’s open to the general public, before the security checkpoints. You can sleep in there on the benches if you have an early flight the next morning.
But this doesn’t work in all airports. Although this is somewhat rare, some airports prohibit passengers from sleeping in the airport during the night. These airports usually close during the night and only open once the security checkpoints start working again.