What is gate checking?
Gate checking is the process of checking your bag at the gate to be stored in the cargo hold of the aircraft. This is different from regularly checking your bag, as the process is normally completed at a check-in desk/ticket counter pre-security, rather than at the departure gate before you board your flight.
When will you have to gate check your bag?
Gate checking is common on smaller airlines. This is because these airlines don't always have the cabin space for all passengers to bring a piece of baggage with them on-person.
Some airlines will tell you specifically that you have to check your bag in at the gate at the time that you buy your flight as a rule that applies to all passengers, whereas others might use a first-come-first-serve system. A first-come-first-serve system means that the airline will allow as many carry-on bags into the cabin as will fit in the overhead lockers, but, once it reaches full capacity, all other bags must be gate checked.
What are the disadvantages of gate checking your bag
Bringing the bag through security
If you have to gate-check your bag and have no option to check it at a check-in desk/ticket counter pre-security, then you'll have to take your bag through security. Unfortunately, this means that all the items in your bag will be subject to security rules and it will limit what you'll be allowed to take away with you.
Having to wait to collect your bag
One of the downsides of gate checking your bag as opposed to carrying it on board with you is that you'll have to wait for your bag at baggage collection. Usually, if you're only taking a carry-on bag in the cabin, you can skip baggage collection, which really significantly up the post-flight process.
Not having important items on-person
If you have to check your bag at the gate and aren't allowed to bring baggage with you in the cabin, you might not be able to carry all the items that you need during your flight.
Additionally, if you're caught off guard and are forced to gate check because the cabin has run out of space, you might accidentally leave an item in your baggage that you wanted to carry or keep in your pockets i.e headphones, a book, or in worse cases, your passport!
How to avoid gate checking your bag
Fly on a full-service carrier
Flying on a full-service airline will ensure that your bag isn't gate checked. These airlines put service first and offer spacious cabins with enough room to fit at least one piece of carry-on baggage for each passenger and sometimes more.
Beware of low-cost airlines. Just because an airline flies big aircraft, it doesn't mean that it will have enough space for each passenger to carry a bag in the cabin. Even major names like United, JetBlue, Southwest, easyJet and Ryanair frequently ask passengers to gate check their bag if they run out of cabin space.
Be the first in line to board
One way to beat the first-come-first-serve system is to make sure that you're the first in line to board. Stand in line with your travel documents in-hand before they call for boarding and you'll almost guarantee that your bag will be allowed in the cabin.
Those who wait until the last minute to board are always the ones that run the highest risk of having their bag gate-checked.
Many airlines offer priority boarding that will allow you to board before the other passengers are even called for boarding. This usually comes at an additional cost but it's a sure-fire to avoid getting your bag gate checked.
Are there any advantages to gate checking your bag?
You can get straight off the plane
Because you don't have to retrieve your bag from the overhead locker, you can get straight off the plane and to passport control/immigration quicker. This is especially advantageous when your bag is stored in an overhead locker that's a few rows away from your seat, so you have to wait for everyone else to retrieve their bag before you can get to yours.
It's a fairly quick process
Having your bag gate checked is a fairly quick and painless process. Usually, the bag doesn't have to be weighed and there's no need to drop it on a conveyer belt. It's just a case of a boarding gate staff member putting a tag in on your bag and giving it to a baggage handler to put in the cargo hold.