Plexiglass 1/4" Cat Door Window Insert | Vertical or Horizontal | Easy No-Tools Installation!

I wish I had found this product years ago, but the thought to have a cat door in the window didn't even occur to me. This is a genius product that's saved my AC and home while letting my cats go to and from the patio as they like. Customer service was impeccable. They very quickly responded to me, helping me verify my window measurements. It was 1000% worth it to get the double locking door feature, too. Every night, I lock it so they can only come back inside, and it's saved my arms from scratches! Giving my cats that sense of freedom has made all the difference as they adjust to our new home. I also got the Defender Security locks for the window (same cost as the hardware store but more convenient) for peace of mind, and it helps keep the Cat Flap snug in the window.

I wanted to find a cat door that could utilize my small basement window rather than cutting into a door, and this product was the perfect solution. The staff was great with communicating and answering all of my questions about measurements. I needed to make a slight adjustment to the height after I received it since the edges of my window ended up being higher than normal. They walked me through the steps to trim it with a miter saw and now it fits perfectly. There was a little bit of a learning curve for my cat, but he is now comfortable with using it and I don’t have to worry about bugs and the cold air getting through an open window. Highly recommend this company and this product!

Cats love it, but door locks unintentionally and that is not good. My cats get either locked in or locked out. The locking clips are located on the bottom edge and somehow as they walk in or out the clips slide. I was told to put tape on them to remedy the situation. Not a good answer! So now I have to put tape on/off daily?? So if you want control of your lock on a daily basis I would skip this door. Otherwise it’s great.

The company rep called to clarify measurements because I had input conflicting info. They informed me I would receive a partial refund, even though it had been my error. In spite of that the cat door arrived amazingly fast. It fits perfectly! Great company! Highly recommend!

I bought this Plexiglass Cat Window in November 2025. It's August 2026 and it's still going strong and in great condition and quality. The customer service to gather our exact measurements was seamless and the video provided is very helpful. The easiest installation ever. We went with the wider size for my big boy and the extra space was perfect.

I bought this because I was getting tired of getting up all the time to open our patio door to let our 3 cats out/in. What I didn't know is how much HAPPIER my cats actually are. We have an enclosed backyard, so now they freely come in and out as they please. The lock option is great for at night, where we prefer to keep our cats safe indoors for potential predators. We live in Texas where Coyotes have been seen occasionally. My cats seem to be living a much fuller life with this cat window. They are even using the outdoors to go to the bathroom. It's been beyond wonderful and such a great investment! Thank you to Cat Flap Fever!

Excellent service ! I entered a measurement incorrect and they called to verify what the actual measurement was. The product is received was excellent quality. My cat learned to use in in about 2 days .

This is a wonderful custom product with great service! I spoke with Barb multiple times who answered all of my questions and helped me measure for a perfect fit.

It’s such an upgrade from the door I had. I highly recommend!!!

I wanted a window cat flap so my cat could have access to her outdoor catio whenever she wanted. I'd previously ordered a basic premade one from Chewy, but the flap itself was quite small, you couldn't see through the material, and the way the flap was positioned, she couldn't get to her favorite ledge. So I ordered this one, and it's a huge improvement! I love that the plexiglass doesn't block the view, the flap itself is larger and good quality, and the custom positioning is exactly right. It seals well and doesn't let in bugs or let out my air conditioning. It's perfect! I was worried about measuring correctly, but it was easy to do and couldn't be easier to install. I would recommend this brand to anyone.

The plexiglass insert fit perfectly in our window. The instructions for measuring were super clear. The folks were quick to reply to any questions and shipping was fast. Be sure to specify if you want a four-way flap. Our cats learned how to use it pretty quickly. As it is a piece of Plexi, it is not double paned and may be a little drafty, but we'll probably just close the window when it gets super cold. But they do put weather-seal type material on all the edges for a tight fit. And it's MADE IN THE USA!

Access to Catio with this plexiglass insert is wonderful!
I’m happy and so are my 2 cats.

I converted a window with plexiglass and cat door previously. It worked well. This Cat Door Window Insert should have been in my life a lot earlier! It only took about 5 seconds to install. It works perfectly. My cats love it. I’m no longer a “door man”. Looking for a new career.

Great quality. Perfect fit. Price seemed high but it lived up!!

We recently got new windows installed. We have a catio and had a 20 yr old thermo sash cat flap in the old wooden windows. It did not work with the new windows. Found nothing on Amazon but eventually stumbled across Cat Flap Fever. I sent photos of the window and what we had to work around. We came up with a plan, they made it and it works beautifully. And unlike the old thick metal cat door, this one is bright and open like the window. We are pleased as are the cats.

I ordered two of these (I recommend the clear plexiglass ones) for the new catio we were building and the customer service was on top of making sure our orders were correct and making it easy to send back when it wasn’t just right.

I purchased a cat flap for my catio. It comes from my bedroom window out into our catio. I love love love the cat flap window. I have for years left my window partially open so the cats can come and go into the catio. This is allowed cool air to come in during the winter and hot air during the summer and of course insects at times. My window is not very large so I was a bit taken back at the price. But I’m glad I went ahead and bit the bullet and did it. My eldest cat is already using the flap with no problem. My semi feral kitty is still not going through it. I hope she will eventually learn by watching the other Kitty.

I love my new cat flap door. It allows me and my brother to go out on the enclosed deck night or day. We love the fresh air and watching all of the wildlife. Our mom likes it because the plexiglass is so clear and clean and does not interfer with the view

I received my vertical window cat flap and it is a perfect fit. It is for entry into my screened lanai. It arrived within a few day. I am a 69 year old woman and it was easy to install. I did not look at which side the locks were and accidentally installed it backwards. But it wasn’t a problem taking it out and putting it back in the correct way . My cats are both 6 months old. The one cat figured it out in two days, the other one it was a little over a week. But he is slower learning everything. I did leave the window cracked open for them & had them using the window for a week or two before I ordered my insert which seemed to help with the learning curve.