Pet Doors for Sliding Glass Doors

It is true that cats can instantly adapt to living indoors and they acclimatize exceptionally well.

However, as familiarized as they are with their indoor territory, they still need to convey their need to give in to their natural feline demeanour.  That urge of going out where they can scratch, climb and explore the realm that is outside the private nooks of indoors.

Pet doors for sliding glass doors can easily be installed without tools or cutting. There are three options for you to choose from:

  1. Freedom® Aluminum Patio Panel by Petsafe– manually opens, no cutting required.
  2. Patio Pet Door (Fully Automatic) by High Tech Pet– fully automatic, works with a pet collar. Automatic deadbolt lock.
  3. Thermo Panel 3e by Endura Flap– fully automatic works with pet’s micro-chip. Fits almost all track heights, spring-loaded.

It would be inconvenient for a cat owner to have to slide open and close the door every single time pets have these outdoor urges.

But, you don’t have to be anymore. Not with the cat door for your sliders.

Cat Doors for Sliding Doors

PetDoors have had over 500,000 happy customers since 1976 for their different products that are particularly focused on giving your pets access to both indoors and outdoors.

They have a line of pet door designs that are particularly designed for sliding glass doors.

These do not require you to cut through your existing glass door if it is your first time to install one.

Rather, you can simply fit it in with just a few modifications. We’ve checked out a few pet doors that can be helpful for you, your feline, and your sliders.

Freedom® Aluminum Patio Panel by Petsafe – Cat Door for Sliding Patio Doors

Product Link: PetSafe Freedom Aluminum Patio Panel Sliding Glass Cat Door

PetSafe Freedom Aluminum Patio Panel Sliding Glass Dog and Cat Door, Adjustable 76 13/16 in to 80 11/16 in - Medium White Pet Door

Utilizing your sliding door as an access way for your pets is easy with the Freedom® Aluminum Patio Panel by Petsafe.

It doesn’t leave you confused with complicated instructions. No drilling. No sawing.

This door panel for your cat comes in different sizes. Your convenience starts by picking the right pet door with the correct height measurement of your sliding door, height and width of your pet, and your color preference.

Freedom® Aluminum Patio Panel by Petsafe comes in different sizes so you can choose from 81 to 96 inches.

Petsafe has designed their panels with different sizes according to your pet’s size, for your selection – from the smallest at 5 x 8 inches to the largest at 14 x 24 inches.

It is perfect for homeowners and renters as you can just slide them in or detach them fairly easily.

Worried about the hot or cold weather outside? Petsafe incorporated it with tinted and flexible flaps that have magnetic closure to resist weather from altering the interior conditions.

Freedom® Aluminum Patio Panel consumed aluminum to create a high-quality frame. It makes this cat door durable while being lightweight.

The design and construction allow for a better hold on the door. It is rustproof and there will be no need to replace the door for quite a long time


  • Quick Installation – You can DIY without cutting into walls or doors. Adjustable from 75 7/8 inches to 80 11/16 inches to suit into your door frame
  • Different Sizes and Colors – You can choose from satin, white, and bronze that blend really well with your sliding glass doors
  • Strong and Durable – They are designed and manufactured to withstand heavy use, the door is built with weather-resistant aluminum and shatter-resistant tempered glass
  • Controlled Access – The slide-in closing panel lets you securely control your mouser’s access to the outdoors.


  • Easy to install and setup. Perfect cat door for renters
  • Is provided with a weather-resistant panel and stripping
  • Manufactured with superior and high-grade aluminum and shatterproof glass
  • Comes with energy-saving ultra-seal
  • Available in different sizes and colors


  • May take up a huge chunk of your sliding door space
  • Makes insulation limited

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Patio Pet Door (Fully Automatic) by High Tech Pet

Product Link: Power Pet Fully Automatic Sliding e-Glass Pet Door

Power Pet Fully Automatic Sliding e-Glass Pet Door (Regular 75

If you are a fur parent who worries about unwanted animal friends coming over for a visit, Patio Pet Door by High Tech Pet is your best choice. This pet door is sensor-triggered and only opens from the prompt set off by the pet’s battery-operated collar.

Patio Pet Door by High Tech Pet does not just open at the nearness of the pet from the door, like most doors at the mall do.

The directional process is activated only when your pet is directly approaching the door, not when it is sitting or nosing around nearby.

A secure pet door it is designed to be, it is constructed with weather-proof construction with automatic settings to keep unwanted costs of using a pet door.

It is mounted in an energy-efficient dual-pane, low-E glass panel that easily fits into an existing sliding glass door.

The self-contained pet door adjusts to your slider’s individual height with the help of a special spring-loaded top section for that quick and easy installation.

Your slider glides shut against the pet door’s insert and may be locked with its incorporated Universal Quick-lock that is designed to work with almost any sliding glass door.

In less than an hour, your sliders would have been installed with a safe access point for your pet that has full weather-stripping and increased home security.

The whole panel is constructed with a steel deadbolt lock and bulletproof door panel that, when triggered by your pet’s collar, instantly and discreetly disappears into a sophisticated housing.


  • Full Power, Motorized Operation – Keeps stray animals away while giving your pets the freedom to come and go without making you a doorman.
  • Installs Right Alongside Your Existing Sliding Glass Door – Installs in no more than 30 minutes without cutting or drilling.
  • Double Pane Energy Efficient Glass for Extreme Climates – Full weather stripping is included. No heat or coldness from the outside comes in.


  • Fully automatic with collars for pets that are safe to use
  • Sturdy and durable construction
  • Automatic deadbolt lock and safety retract system


  • The battery used for the collar dies down easily

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​Thermo Panel 3e by Endura Flap

Product Link: Endura Flap Pet Door Thermo Panel 3e

Endura Flap Pet Door Thermo Panel 3e - Medium Flap (8

It started out from the frustration of not finding the good flap on a pet door.

In Endura Flap founders’ opinion, those in the market were either too rigid or not safe enough. They could be flexible but it didn’t give the right insulation.

After many hours of engineering and testing, they finally perfected the safe flap in 2005 – the birth of Endura Flap® design.

A perfect option for adding a secure way of permitting your cats in and out, Thermo Panel 3e has a four-lock system that retains it firmly in place and keeps the door locked until triggered.

Same as Patio Pet Door by High Tech Pet, Thermo Panel 3e by Endura Flap, the door lock is triggered by your pet’s embedded microchip, reducing the need for an external remote tag that could either be lost or damaged.

With its high-quality construction and sturdy materials, Thermo Panel 3e by Endura Flap can keep both large and small unwelcome animals out.

It is energy efficient with its dual-pane LoE glass and Endura Flap Pet door built into a tough aluminum frame.

Installation does not require tools. Its 3 inches spring-loaded height adjustment allows for easy setup and removal.

The single dual-layered flap is semi-transparent and it seals in contrast to the weather using a patented system of magnets.


  • Easy Installation – No tools required. Just slide into aluminum sliding glass doors with its U-shaped tracks at least 1 inch thick.
  • Weather Resistant – Flaps are dual-layered with translucent sealings against the outside weather.
  • Different Sizes and Colors – 74 ¾ inches to 93 ¼ inches / White, Dark Bronze, Brushed aluminum


  • Fits almost all track heights
  • The spring-loaded design ensures a simple installation and is removable
  • Microchip sensing technology that is perfect for pets that refuse to wear collars


  • Microchip positioned too low, cats will have to crouch down
  • Lack of weatherproofing around the hard plastic door

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​Can You Install Cat Door in A Sliding Glass Door?

Yes. Patio panel pet doors, as what they are commonly known are pet doors for sliding glass doors. They are a simple yet effective solution for giving your cats and other pets easy access in and out of the house.

Setting up of cat doors for sliding glass doors aren’t complication since they can go with the existing track on your sliders.

Most patio panel pet doors can be installed without having to drill into your door or wall.

As much as it sounds like you have to replace your existing sliding door, you don’t. These can be easily fitted into your sliding glass doors with just minor modifications.

Here are the basic steps to follow in installing a pet door into alongside your existing sliding doors.

Step 1. Check Your Door’s Design

Examine your sliding door and gauge its track. Check whether your sliding door’s track is a monorail or not.

Installing a pet door on a sliding door that is not on the monorail is easier since the panels can be adjusted easily. But, if it is monorail, you can get monorail adaptors available at most DIY stores.

Once you insert the panel, it forms a partition that partitions the whole door into two parts – one being the immobile panel with the pet door and the other being the established panel of your door.

Step 2. Consider and Take Your Pet’s Measurement

The flap size should be according to the size of your pet so it is important you take measurements first. Otherwise, the pet door may be too big or too small for your pet and may just cause injuries.

To measure your furball, take the extents of the widest part of the cat’s body and add approximately 2 inches to it.

For the length, take the measurement by gauging from its shoulder to its feet and add about 1 inch to it.

Measuring your pet correctly will guarantee that the flap is just of the right size for the pet, enough for them to comfortably pass through every single time.

This also keeps larger animals from entering your house from the outside through your flaps.

Step 3. Positioning the Flap on The Door

Before installing the flap on the door, try cutting a piece of cardboard to test. This should give you an idea of where to perfectly position the flap in the sliding door.

Place the flap in a corner so as to not disrupt the functioning of the sliders. Corners are also convenient and ideal for pets to pass through.

Step 4. Measuring the Sliding Door

The next step in installing the cat door to your sliders is to accurately measure the sliding door and space you are willing to give to the pet door.

This is because after installing an extra panel for the pet door, the area of your sliding door will decrease.

Measure both door and panel as the size of the panel will incorporate the width of the flap you will add.

Once you are finished taking the measurements, you will be able to determine the perfect pet door that’s just enough to for your pets to pass through without taking too much space from your sliding door.​

Take note of the things you need to look for in a cat door;

  • Flap Size
  • Flap colour and shape
  • Security of access
  • Ease of installation
  • Durability

Step 5. Dry Fitting the Panel

Once you have the panel and the items you need to install them with, dry-fit to see if there are any alterations needed to be done.

Dry fitting should give you an idea of how your door will look like after any modifications.

Step 6. Fitting the Panel In

After dry fitting, the panel and once everything looks perfect, fit the panel in the sliding doors.

Place it in the bottom track and position it in the spot you think is the best for your fur babies. Tighten it by twisting the screws from the bottom to make it firm and stable.

There is a pressure system that works for sliding doors where towards the top end, it expands and fits in the height of the track. The panels can fit perfect even with this kind of system since you can just pop it in and out.

Step 7. Finalizing the Installation

Once the panels are stable and they are a snug fit into your sliding door track, the last thing you need to do is to install any insulation of weatherproofing devices that may come with the panel.

Manufacturers usually have the instructions listed on a user’s manual as it depends on each type and model.

How Much Does It Cost To Put A Cat Door?

The cost of pet doors varies upon the materials and how they are constructed.

A simple cat insert with plastic flap plays around $25 to $50, while that for a wooden door would be around $150. For sliders, electronic sliding pet doors range from $200 to $1000 depending on the size.

Installing the pet door in a sliding door should be pretty simple and can be done without any help. However, the level of difficulty also varies upon the location where it is to be installed.

It wouldn’t sound so bad to hire a professional if you are looking at putting it on an existing door, especially a sliding glass patio door, or if you need to cut through a wall.

Hiring a professional will cost you $125 to $300 on top of what you paid the pet door for. Some may charge either by the hour or per project. The fee may also increase if the handyman is the one providing the door.

Is There A Difference Between a Cat Door And A Dog Door?

It is easy to say that there is not much difference between a pet door for cats and dogs, after all, they are doors for pets. But, anatomically speaking there are slight variances between them.

For instance, cats have wider bodies that are relative to their height, thus they need wider and shorter doors. Dogs’ doors are typically taller and narrower.


Adding a cat into a household is a decision to be responsible for their needs. Such needs include having to breathe and do their own thing beyond the four corners of your house.

An expenditure of $500 may feel too much for a cat door. But, imagine what you will spend for the accidents in the house that includes scratching, barking, breaking things – all associated with a cat wanting to get out.

Adding a pet door in your existing sliding glass door is a brilliant option for giving your cat outdoor access.

Instead of being a gatekeeper, cutting or drilling a hole through your wall for a pet door, a patio panel allows them feline freedom to conveniently go in and out of the house without distressing you.

There are a lot of panels in the market that will work with your sliding glass door and they all typically follow the same installation process, with just a few differences.

All you need to do is pick the right size that is just right for you and your cat’s need.

For other ways to keep your cat happy and healthy, read the updated guide on scratching posts here.