If you want your cat to move between the house and patio without waiting for you to open the door, a sliding-door pet insert can be a practical solution. The best choice depends on your door-track measurements, the space your pet needs to pass through, and whether you want a glass panel, a screen, or extra ways to control access. These five options fit different needs, from a cat-sized flap to a screen insert that also lets fresh air in.
Table of Contents
Quick Comparison
| Product | Type | Stated height fit | Notable feature |
|---|---|---|---|
| MfeCylizth Adjustable Sliding Door Pet Insert | Transparent panel with pet flap | 75.79–81.34 in | Adjustable height and weather-resistant flap |
| Petoasis Cat Door for Sliding Glass Door | Glass-panel insert for cats | 76⅜–80⅝ in | Cat-sized flap and four locking modes |
| Hakuna Pets Tempered Glass Patio Insert | Glass-panel insert for cats and small dogs | 77.2–83.5 in | Tempered glass, magnetic flap, and security panel |
| PetSafe One-Piece Sliding Glass Pet Door | Glass-panel insert for cats and small-to-medium dogs | 75⅞–80 11/16 in | Medium flap fits pets up to 40 lb |
| Hakuna Pets Mesh Screen Insert | Screen panel with pet flap | Adjustable; confirm your door measurements | Fiberglass mesh for airflow and insect protection |
Our Picks: Best Sliding Glass Door With Cat Door reviews
1. MfeCylizth Adjustable Insert for a Straightforward Fit
The MfeCylizth insert is a full-height transparent panel designed to fit into a sliding glass door track. Its adjustable height range of 75.79 to 81.34 inches gives it some flexibility for homes where a fixed-size panel would not fit. The transparent panel also helps preserve the view through the patio doorway.
The product description highlights a sturdy, weather-resistant flap intended to help limit drafts, rain, and debris. That makes it a sensible basic option if your main goal is giving a cat or dog access without repeatedly opening the sliding door. However, the supplied details do not state the flap opening size, a locking system, or a specific pet weight limit. Measure your pet and confirm those details before choosing it.
Compared with the cat-specific Petoasis insert, this model lists a slightly broader height range but does not provide the same flap dimensions or access-control details. It may suit shoppers who want an adjustable transparent panel and do not need a detailed set of locking modes.
Pros:
- Adjustable height from 75.79 to 81.34 inches
- Transparent panel helps maintain visibility
- Weather-resistant flap is designed to help reduce drafts and debris
Cons:
- Flap opening dimensions and pet size limits are not specified in the supplied details
- No locking system is listed
Verdict: Choose the MfeCylizth if its height range matches your doorway and you want a simple transparent insert, but verify flap sizing before ordering.
2. Petoasis Cat Door with Four-Way Access Control
The Petoasis is designed specifically for cat owners who want a compact flap rather than a larger opening intended for dogs. Its flap measures 7.7 inches wide by 8.6 inches high, so check your cat’s width and height against those dimensions. The insert adjusts from 76⅜ to 80⅝ inches and is described as fitting tracks at least 0.8 inches wide.
Its aluminum frame and transparent tempered-glass panels give it a more finished, door-like appearance than a basic screen insert. The flap has felt lining and a magnetic closure, while the four-way sliding latch offers exit-only, entry-only, two-way, and fully locked settings. Those modes provide useful control when you want to limit when your cat can use the opening.
The trade-off is the more specific fit: the stated height range is narrower than some alternatives, and the insert uses about 12 inches of track space. The product description also calls for measuring carefully, so check both the opening and the available space alongside your sliding door before buying.
Pros:
- Cat-focused 7.7-by-8.6-inch flap opening
- Four locking modes offer flexible access control
- Aluminum frame and transparent tempered-glass panels
- Spring-loaded, no-cut installation
Cons:
- Narrower height range than some other inserts
- Uses about 12 inches of track space beside the door
Verdict: The Petoasis is a strong match if you want a cat-sized flap and multiple access settings, provided your track and doorway measurements meet its requirements.
3. Hakuna Pets Tempered Glass Insert for Cats and Small Dogs
This Hakuna Pets model uses a tempered-glass panel in an aluminum frame, making it a more substantial option than a mesh insert. Its 6.7-by-9-inch flap is intended for cats and small dogs up to 20 pounds, with a 2-inch step-over. The stated fit range is 77.2 to 83.5 inches for compatible aluminum sliding-door tracks.
The magnetic flap is designed to close on its own, while rubber and foam seal strips help reduce drafts, wind, rain, and bugs around the frame. Installation can be temporary with its spring-jack pressure mount or made permanent with the included brackets. A metal security panel slides over the flap to block pet access when needed.
Track compatibility is an important limitation. The product description says it works with Track-Lip and U-Channel tracks, but not Flush, Narrow, or Bifold tracks; it also is not intended for walls, windows, screen doors, or wooden doors. Its flap is smaller than the PetSafe medium option, so it is better suited to cats and small dogs than larger pets.
Pros:
- Tempered-glass panel and rust-resistant aluminum frame
- Magnetic self-closing flap with weather-seal strips
- Pressure-mounted or permanently installed with brackets
- Metal panel blocks the flap when you want to restrict access
Cons:
- Limited to specified aluminum track styles
- Small flap is not intended for medium or large dogs
Verdict: Pick this model if you want a glass-panel insert with flexible installation and your sliding door has one of the compatible track styles.
4. PetSafe One-Piece Panel for Pets up to 40 Pounds
The PetSafe medium insert has a larger flap than the cat-focused options in this group. Its opening measures 8¼ inches wide by 13 3/16 inches high, and it is intended for cats and small-to-medium dogs up to 40 pounds. The listed step-over height is 1¾ inches. As always, your pet’s chest width and shoulder height matter more than weight alone when checking fit.
The assembled panel adjusts from 75⅞ to 80 11/16 inches and slides into an existing track without cutting into a door, wall, or frame. It has a weather-resistant aluminum frame, shatter-resistant tempered glass, a glass sweep, and a magnetic flap. A closing panel covers the pet opening, and an included latch kit lets you lock the sliding door once the insert is in place.
At 11½ inches wide, the panel takes up part of the human walk-through opening. That is worth considering in a narrow doorway or busy household. It offers a larger pet opening than the Petoasis or Hakuna Pets glass insert, but it does not have the same four-way access control as the Petoasis.
Pros:
- Large flap opening for cats and small-to-medium dogs
- Adjustable height fits a broad range of standard door heights
- Tempered glass and weather-resistant aluminum frame
- Includes a closing panel and sliding-door latch kit
Cons:
- Panel occupies 11½ inches of walk-through space
- Measure the flap against your pet rather than relying on weight alone
Verdict: The PetSafe is a practical choice if your pet needs a taller flap and you can spare the panel’s width in the doorway.
5. Hakuna Pets Mesh Screen Insert for Fresh-Air Access
Unlike the glass-panel inserts, this Hakuna Pets model combines a pet flap with a full-height fiberglass insect screen. It is designed to sit in a sliding patio-door track and lets air pass through while helping keep insects out. Its tool-free, no-drill setup is removable, which can be useful if you rent or want to take the insert down when you do not need it.
You can choose from three flap sizes: small at 6.7 by 9.1 inches, medium at 8.9 by 12 inches, or large at 11.2 by 15.9 inches. Each has a 1.4-inch step height, and an optional bottom riser adds 3 inches. A magnetic catch helps the flap return to its closed position. Included weather panels can cover the opening when you want to block wind, rain, or other outdoor elements.
This design is the best fit for warm-weather airflow, not for shoppers who want a solid glass panel. The product description does not provide a specific adjustable height range, so check the current fit guidance and measure your track before ordering. The magnetic hold is not a keyed security lock, which is an important distinction if restricting access is a priority.
Pros:
- Fiberglass mesh allows airflow while helping keep bugs out
- Three flap sizes accommodate different pet sizes
- Tool-free, removable installation suits rental homes
- Weather panels let you cover the opening when needed
Cons:
- Specific insert height range is not stated in the supplied details
- Magnetic flap hold is not a keyed security lock
Verdict: Choose this screen insert if airflow and insect protection matter more to you than a solid glass panel or a keyed access lock.
How to Choose a Sliding Glass Door with a Cat Door
Measure the door track and available height
Measure the height inside the track where the insert will sit, rather than estimating from the room or the glass panel. Compare that measurement with the insert’s stated height range. Also check the track style and width: some models fit only certain aluminum tracks, and one listed option requires a track at least 0.8 inches wide. If a product does not provide a clear height range, confirm compatibility with the seller before ordering.
Check the flap against your pet’s body
Measure your pet’s chest at its widest point and its height at the shoulders, then compare those measurements with the flap opening. A pet’s weight alone does not tell you whether it can pass through comfortably. Consider the step-over height too, especially if your cat is small, older, or hesitant about raised thresholds.
Choose glass or mesh based on how you use the doorway
A glass-panel insert is a better match if you want a solid panel and a clear view through the patio door. A mesh insert can be more useful when you want airflow and insect protection in warm weather. The screen option described here includes weather panels, but those are not the same as a full glass panel.
Decide how you want to manage access
Think about whether your pet should always be able to pass through, whether you need to limit entry or exit, or whether you want to close the flap at certain times. Some inserts include a closing panel or several locking modes, while others describe only a magnetic flap closure. A flap that closes on its own is not necessarily a security lock.
Consider installation and rental restrictions
Many inserts are designed to fit into a track without cutting the door or frame, but installation methods differ. Options include spring-loaded or pressure-mounted designs, removable panels, and models that can also be secured with brackets. If you rent, look for a removable installation and check your lease before making permanent changes.
Account for the space the panel uses
A full-height insert sits beside your sliding door and reduces the space available for people to walk through. Check the insert’s width and think about how much of the doorway will remain open for household traffic. This is especially important in a narrow patio entrance.
Frequently Asked Questions
Can I install a cat door insert without cutting my sliding glass door?
Several options in this guide are designed to fit into the existing sliding-door track without cutting the door or frame. Installation details vary by model, so confirm whether the insert is pressure-mounted, spring-loaded, or intended for permanent installation with brackets.
How do I know which flap size my cat needs?
Measure your cat across the widest part of its chest and from the floor to its shoulders. Compare those measurements with the flap’s width and height, and allow enough room for your cat to pass through without squeezing.
Will every sliding-door pet insert fit my track?
No. Door height, track width, and track style can all affect compatibility. For example, the Hakuna Pets tempered-glass insert specifies compatible aluminum track styles and excludes several others. Measure your track and read the model’s fit limits before choosing.
Can I still use my sliding glass door after adding an insert?
The inserts sit beside the sliding door in its track, so the panel reduces the space available for people to pass through. The product descriptions do not state that every sliding door will operate identically after installation. Check the installation instructions and consider the remaining walk-through width.
Do magnetic flaps lock the pet door?
A magnetic closure can help a flap settle back into place, but it does not necessarily lock the opening. If you want to restrict entry or exit, choose an insert that specifically lists a locking system or a closing security panel.
Is a mesh insert a good choice for cold or rainy weather?
A mesh insert is mainly useful when you want airflow and insect protection. The Hakuna Pets screen model includes weather panels for covering its opening, but shoppers who prioritize a solid panel and weather seals may prefer a glass-panel insert.
What is the best overall option for a cat?
For a cat-sized opening with several ways to control access, the Petoasis is a compelling fit if its height and track requirements match your doorway. If airflow is your priority, consider the Hakuna Pets mesh insert; if your pet needs a larger opening, compare the flap dimensions of the PetSafe model with your pet’s measurements.
Final Recommendation
For a dedicated cat door with clearly stated flap dimensions and four access modes, the Petoasis is the most tailored choice, as long as your sliding-door track meets its fit requirements. The Hakuna Pets tempered-glass insert is a useful alternative for compatible aluminum tracks, while the PetSafe offers a taller opening for larger cats and small-to-medium dogs. Whichever option you choose, measure the track, remaining doorway space, and your pet before ordering.
