Best Security Lock for Windows 2025

Windows are the most unsecured part of a house; therefore, it’s reasonable to protect them with different tools and devices if you want to feel safe. One of them is a secondary lock for windows that can give you extra peace of mind. The reason is that basic locks are not usually enough to protect you home from intruders. These little and not expensive things can prevent dangerous situations and keep your property and your life secure.

How to choose the right window lock If there are so many various locks on the market? This is not an easy task. That’s why we want to tell you about 17 best window locks we have found on the Amazon.

TOP 20 Best Window Locks/ Security Locks for Windows / Sliding Window Locks

#1 Prime-Line Defender Security U 9819 Sliding Window Security Lock

The first item on the list is the pack of 4 absolutely standard additional locks for windows. They are made of aluminum and easily blend in any existing interior. These locks have two available window positions: open and ventilating. Locks fit for up to 1/8In. wide rail.

#2 Maxdot 4 Sets Sliding Aluminum Window Locks

The next pack of 4 window locks with aluminum alloy and stainless steel screws is a one-step higher than the previous one. These locks are more durable and flexible. Locks can be applied to tracks with the height over 1.5 cm/0.6 inches and thickness 1.53 cm/0.63 inch and less. You can even use multiple locks to lock heavy doors or windows. However, do not forget to measure your window track before purchasing.

#3 ALLWIN Sliding Window Security Lock with Key

Let’s get a little further and take a look at some more expensive stuff. This model is a pack of 2 aluminum windows stoppers. Their outstanding feature is a non-slip silicone pad on each lock, which increases the strength of locking. These locks have the same installation method: just adjust the clamping distance (between 10 and 60 mm/ 0.39 – 2.36 inch), place a lock on your window frame, and insert the key that turns either clockwise or anticlockwise to adjust the width.

#4 Prime-Line U 9809 Sliding Window Lock for Vinyl Windows

These locks are designed for vinyl windows of horizontal sliding and vertical sliding. The pack includes 2 beautifully designed white adjustable jaws with “Vise like” grips that can keep windows securely locked or partially closed. Locks fit vinyl frame rails of 1/16 to 1/2 inch thickness. The installation is easy and requires no additional tools. The price is a little above average.

#5 Momentum Brands Sliding Window Locks Set

If you need something simple, cheap, but solid, you would probably like these locks. There are 8 stoppers in one pack so you can lock up to 8 windows simultaneously. It’s super easy to install these ones, by the way. The only peculiarity is that they are not compatible with double panel windows. Therefore, make sure you have traditional windows before buying.

#6 1st Choice Sliding Window Lock

Another simple solution for making your home or any other place you want safer. 4 aluminum locks that can be easily applied to almost any rail by screwing in. Such locks are durable, easy to install, and cheap. It makes them a great and pretty affordable purchase. The only downside of this competitor is the clamping distance.

#7 Truestyle Sliding Window Locks Set

The next model actually doesn’t differ from the previous one, except for the brand and price. These 12 aluminum locks are extremely cheap, compared to other models. You can use them for horizontal sliding and vertical sliding windows.

#8 Lion Locks Aluminum Sliding Door and Window Lock

Although these stoppers are not expensive too, they are a little more functional. They can be used for patio doors, sliding windows or doors, and so on. The locks are made of aluminum with an inner vinyl lining that is made to prevent scratching damage. The maximum suitable track wide depends on whether there is rubber on a track or not. Locks suit tracks with rubber that are up to 3/16 inch wide. Otherwise, they could fit even 3/8 inch wide tracks.

#9 Maxdot Adjustable Sliding Aluminum Window Locks

It’s kinda complicated to come up with something new or at least different in this niche. But still, models can differ from each other in several aspects. These aluminum double-locks with plastic cover on the key handle ensure more solid friction force and can be applied to windows and doors with tracks that are not higher than 1.5 cm/ 0.6 In and not thicker than 1.6 cm/ 0.63 In.

#10 Onvian Aluminum Sliding Door & Window Lock

These 6 window locks are designed for horizontal and vertical sliding windows and sliding doors and cannot be applied to plastic window frames. Locks are made of rust-proof aluminum alloy and support ventilating position. Make sure these stoppers fit your windows before buying. The thickness should be no more than 0.63 in/ 16 mm and height should be over 0.6 in/ 15 mm. Not suitable for middle tracks.

#11 Prime-Line F 2588 Sash Lock

This lock is quite unique (as much as it could be in this niche) because it suits aluminum, wooden, and vinyl windows of horizontal and vertical sliding. The baked-on white enamel finish makes this lock look beautiful. Mounting holes on this lock are 2-1/16 in. Thus, there are two small downsides: the price and the installation because you will need additional tools.

#12 RELIANCER Sliding Window Lock Set with Keys

To be honest, 4 pieces sliding window locks for such a price seem to not reasonable enough. Despite the very simple design, which is actually an advantage, they have a decent characteristic. The first advantage of these locks is the material. Stainless steel makes the whole construction and the screw rod more durable and solid. The second one is the size, which means that these locks are pretty adjustable. And the last one is that all locks are equipped with no-sliding silicone pads.

#13 Boao Set of 15 Siding Window Locks

Do not worry, we have cheap locks as well here. This pack contains 15 simple and easy-to-install locks made of aluminum alloy. The greatest advantages of such locks are their durability and the price, of course. The most disappointing thing, as always, is the range of suitable sizes.

#14 Prime-Line Products F 2534 Keyed Sash Lock

The majority of locks we have already reviewed come with a built-in key or screw. This window lock that is made of heavy diecast zinc with a beautiful brass finish can be opened with a special key only, which makes it not only secure but also child-proof. Just apply it to your vertical single/double hung sliding or horizontal sliding window made of aluminum, wood, or vinyl and feel safe. It’s not cheap but it works great.

#15 Prime-Line Products F 2628 Spring Loaded Sliding Window Tilt Latch

One more unique lock on our list. This lock consists of two components made of black plastic to be used on single or double-hung tilt-out windows. Such design is called “wrap-around” because one part of the lock attaches to a top rail and the second — to a stile. There are not many decent models for this window type on the market.

#16 Designers Impressions 53713 Satin Nickel Window Sash Lock

Here we’ve got the pack of ten window locks with an interesting design and satin nickel finish. Although there is nothing special about this product, it has some interesting features, such as a 30-days satisfaction guarantee and compatibility. The problem is that these locks should be mounted with screws and they are not cheap. Screws are included though.

#17 Prime-Line F 2590 Sash Lock for Vertical and Horizontal Sliding Windows

The last lock on the list is made by already known brand PRIME-LINE for various aluminum-framed sliding windows. It’s good because it’s durable due to the diecast zinc with a white painted finish, and it's also multi-functional. You can either use this lock as a new stopper or as a replacement for a broken one. Mounting hole centers here are 2-1/4” and latch projection is 3/8”.

We also want to offer you some interesting products for similar purposes that we have found.

Bonus: Childproof Window Lock

#18 Safety Innovations – Childproof Windows and Sliding Doors Safety Lock

This is a pack of 4 locks for windows and doors to make them child-proof. It’s pretty important to be sure that your children are safe and they cannot occasionally trap into an unsafe zone or fall from the window. You can easily install these locks by sticking them with the help of pre-applied heavy-duty tape. For better protection, it’s recommended to use two locks on each window or door.

#19 OKEFAN Baby Safety Slide Window Lock for Kids

Another lock for kid’s protection that has some interesting advantages, such as design and durability. First of all, this lock Is made of high-quality ABS plastic and stainless steel spring. Then, the unique design ensures better safety thanks to the double-button system. Install the lock beside a door shelf by sticking the device wherever you want.

Bonus: Window Security Bar

#20 Ideal Security BK111W Window Security Bar with Child-Proof Lock

One more interesting lock for today. This lock is not that easy to install as previous models, but there is a good side too. Such construction allows you to adjust the size between 10.5″ and 16.5″ (BK112)/ 15.5″ to 26.75″(BK111). Due to the fact that this lock is visible from the outside, this lock scares off intruders.

Conclusion

Secondary locks can do a great help in making your home a safer place. If you want to pick the best of the best, we recommend you to consider the following items:

#3 ALLWIN Sliding Window Security Lock with Key

#12 RELIANCER Sliding Window Lock Set with Keys

#14 Prime-Line Products F 2534 Keyed Sash Lock

Do not forget to check other reviews to stay tuned!