Can a Dog Door Be Installed in a Glass Door?

Yes, but the method depends on the glass and door style. A sliding patio door may accept a separate insert in its track, while a hinged glass door may need a new pane prepared for a pet door.

Don't try to cut a glass panel yourself. Tempered glass is designed to break into small pieces if cut after tempering, and insulated glass units require a suitable replacement to keep the assembly intact.

A glazier can identify the glass type and explain whether a replacement panel is practical. If you rent, check with your landlord before changing the door or frame.

How can you add a dog door to a sliding glass door without cutting?

Use a patio insert that sits in the sliding door track if the track and height match the insert. It creates a separate pet opening alongside the existing glass panel.

Measure the door height at the track and note the track shape. Also measure the opening your family needs: an insert takes up part of the space where the sliding panel would otherwise move.

The PetSafe 96 in Large insert adjusts for track heights from 91 7/16 to 96 in. Its panel is 13 1/2 in wide, and its flap opening is 10 1/4 x 16 3/8 in.

Check your dog's chest width and shoulder height against the flap opening, not just the weight guidance. The panel also reduces the walk-through opening for people, so measure the space you need to pass through.

For more options and fit details, see our guide to sliding glass dog door inserts.

What should you measure before choosing a glass door insert?

Measure your door, track, dog, and human walkway. An insert that fits the door height can still be wrong for the track or your pet.

Measure the door's height where the insert will sit in the track.
Identify whether the track has a lip, a U-channel, or another shape.
Measure your dog's chest width and shoulder height.
Compare those measurements with the flap opening and step-over.
Check how much the insert narrows the people-sized opening.

The Hakuna Pets insert fits certain aluminum sliding door tracks and heights from 77.2 to 83.5 in. Its small flap is 6.7 x 9.3 in, with a 2 in step-over, and is intended for small pets up to 20 lb.

This insert does not fit every track or door type. Check the track shape and height carefully, especially if your door is flush, narrow, bifold, wooden, or a screen door.

Our guide to measuring your dog and door for a pet door walks through the pet and opening measurements. If the sliding door isn't a fit, compare other options in pet doors for dogs and cats.

What if your glass door is hinged or part of a window?

Ask a glazier about a pet-door-ready replacement panel for a hinged glass door. The glass type, pane size, and frame determine whether that approach is suitable.

A sash window is a different setup from a patio door. The Ideal Pet Products Aluminum Sash Window Pet Door is designed for an aluminum sash window, with an adjustable width of 27 to 32 in and a minimum height of 20 3/8 in.

Don't assume a window insert will fit a sliding patio door, or that a patio insert will work in a hinged glass door. Match the product type to the opening before you buy.

For a French door with glass, start with our guide to dog door options for French doors. A glazier can assess the panel and explain whether a replacement is possible.

Is it safe to cut a hole in tempered or double-pane glass?

Don't cut tempered glass or an insulated glass unit yourself. Have a glass professional identify the panel and recommend a suitable replacement or another installation method.

Tempered glass cannot be cut after it has been tempered. A glazier can tell you whether a new pane can be made with an opening for a pet door and whether it suits the existing frame.

Double-pane or insulated glass has multiple panes sealed together. Changing one pane can affect the unit, so ask a professional about a correctly built replacement instead of cutting into the assembly.

If you want to avoid altering the glass, a track insert may work for a sliding patio door. It still needs a compatible track and enough height.

How do you choose the right opening for your dog?

Choose a flap that gives your dog enough room to pass through comfortably. Compare the flap opening with your dog's width and shoulder height, and account for the step-over.

Don't choose by weight alone. A dog can fall within a product's weight guidance and still need a wider or taller opening.

Measure the dog standing naturally, then check the opening and step-over listed for the option you are considering. For more on flap types and sizing, see how to choose a dog door.

What should you check before installing a patio insert?

Confirm track fit, door height, pet fit, and access control before installing. Follow the insert's instructions and check that the sliding door still works as intended.

Some inserts use pressure mounting, while others can be secured with brackets or hardware. If you rent, ask before using any permanent fasteners.

Check how the pet opening closes and how you will secure the patio door. A panel can help control pet access, but it doesn't replace checking the lock and fit of the full door.

If you plan to install a flap in a screen door instead, read how to install a dog door in a screen door. A screen door uses a different frame and installation method.

Which glass door dog door option should you choose?

If your door is a compatible sliding patio door, choose a track insert after measuring the track, height, dog, and walkway. If it is a hinged glass panel or insulated unit, ask a glazier about a replacement pane made for a pet door.

Choose the Hakuna Pets insert for a small pet and compatible aluminum track, the PetSafe insert for a taller sliding door and larger flap, or the Ideal Pet Products model for a sash window that meets its measurements. For more sliding-door choices, compare the best sliding glass dog door inserts.

Frequently asked questions

Can you cut a hole in a glass door for a dog door?

A glass professional should assess the door before any cut. Tempered glass cannot be cut after tempering, and insulated glass units need the right replacement pane to preserve their construction.

Ask a glazier about a pet-door-ready replacement panel, or use a track insert if your door is a sliding patio door.

Can a dog door go in a sliding glass door without cutting?

Yes. A patio insert fits in the sliding door track beside the existing glass panel, so the glass does not need a pet-door opening.

Check the insert's height range, track shape, and width against your doorway, then confirm how much human walk-through space it uses.

Are glass patio inserts suitable for every dog?

No. Inserts have specific flap openings and step-over heights, and some models fit only certain pets or door tracks.

Measure your dog's chest width and shoulder height, then compare those measurements with the flap opening.

Also check the insert's height range and track compatibility.

Can a pet door be installed in a French door with glass?

It may be possible, but the glass panel type and frame affect the options. Don't cut an existing pane without advice from a glass professional.

Read our guide to dog door options for French doors and ask a glazier whether a replacement panel is suitable.

Can a Dog Door Be Installed in a Glass Door?