Best Dog Door for a Sliding Glass Door: How to Choose One

How sliding door dog doors work

Most sliding-door dog doors are insert panels. The panel sits in the door track, the sliding door closes against it, and the dog uses a flap built into the bottom of the panel. They install without cutting glass, which makes them popular with renters, and can be removed when you move.

The alternatives are a pet door built into a new glass pane, which needs a glazier and costs more but looks cleaner and seals better, or a door installed through an adjacent wall. For most homes and rentals, an insert panel is the practical choice. You can browse dog doors for sliding doors once you know your track height.

What matters most

Fit comes first. Measure the height of the track opening from the bottom track to the top track precisely, because panels are sold in height ranges and adjust within them. A panel that does not reach snugly will rattle and leak. Check which side of the door the panel will sit on and that it suits your door's frame.

Flap size comes next. The AKC advises choosing the door for your largest dog, because a door that is too small can frighten a dog or be dangerous if it gets stuck, and says small dogs must be able to open it easily. Measure your dog's shoulder width and the height from floor to shoulders, and choose a flap the dog can pass through without ducking or squeezing.

Weather and security

Insert panels are a gap in your door, so sealing matters. Look for weatherstripping along the edges, a double or magnetic flap that closes firmly, and an insulated or dual-pane glass section in cold or hot climates. Some owners add a bar or lock to the sliding door so it cannot be forced open with the panel in place.

The AKC suggests placing a dog door away from locks or latches someone could reach through. A lockable slide-in cover lets you close the flap at night or when you are out. Electronic flaps that open only for a collar tag or microchip keep out wildlife and neighborhood cats.

The best type for each home

For renters, a tension-fit insert panel that installs without screws. For cold climates, a panel with an insulated glass section, double flaps and good weatherstripping. For large dogs, a tall panel with an extra-large flap (see large dog doors) and a step-over height low enough for older dogs. For homes with wildlife or stray cats nearby, an electronic flap.

For multiple dogs of different sizes, size for the largest and make sure the smallest can still push the flap. For a senior dog, keep the step-over low and the flap light.

You can compare panel heights and flap sizes across our dog doors range before measuring your track.

Training and care

Dogs often need training to use a new door. The AKC suggests starting with the flap held or taped open, coaxing your dog through with treats and praise, then gradually lowering it. Keep sessions short and positive. Never push a dog through the flap.

Clean the flap and seals regularly, check that magnets and weatherstripping still close firmly, and replace a cracked or curled flap, or check dog doors for sliding doors for a new panel. Make sure the yard your dog reaches is safely fenced, and that you can still check on your dog; talk to your vet if a door gives a dog with health problems unsupervised outdoor access.