16 Types Of Window Locks (Uses & Styles)

Windows are one of the most vulnerable points of entry in the home. Burglars can easily get in through the door without breaking in. This is why it’s also important to secure your windows with locks to deter intrusion in your home.

Man opening window lock

Here are the different types of window locks you should be mindful of.

Window Latch Types

Close up of black window folding lock

A latch is a common type of lock located in the sash’s middle or top part. The latch consists of a lever or handle and connects the two parts of the frame, keeping it closed or locked. 

A latch can work with both single-hung and double-hung windows. Simply turn the latch to secure the opening.

Folding Lock

Gray window folding lock with mosquito screen

Folding locks are also known as folding latches. They are typically used with top-hung windows, such as casement and awning styles. 

Once they’re installed on the sash, you just need to fold the latch down to ensure that the pane stays locked. If you would like to open the window, simply pull the latch up.

Keyed Locks

Close up of keyed lock for window

Its name is probably a dead giveaway. Keyed locks are types that require a key to secure the opening.

They’re usually mounted on a sash or frame. These types can work with various windows, from single-hung to double-hung and even sliding windows.

Most homeowners find keyed locks a bit bothersome. This is mainly because there are so many keys to keep track of if all the windows in your house use this lock mechanism. 

Window Wedge

Close up of window wedge lock

A wedge lock is a rather unique style as it was designed specifically for emergencies. Fun fact: this lock was designed by a retired detective from the NYPD. It attaches and detaches from the frame quickly, making installation a breeze.

This lock can work with single, double, or even horizontal sliding windows. It has a wedge and an 8-inch string loop that can prevent the window from opening.

These wedge products are great for keeping small children safe, especially since there have been incidents wherein children have fallen out of windows.

Window Pin Lock

Pin lock set for sliding doors and windowsCheck out this pin lock at Amazon [sponsored link]

Window pin locks are fairly simple but efficient locking mechanisms to secure your home. A locking pin is installed on one of the sashes, whereas the other has a latch that the pin can get into to keep the windows locked, effectively keeping intruders out. 

The pin typically stays with the latch that’s attached to the frame.

Chain Lock

Window with chain lock

Chain locks are pretty versatile, not just for window use but also for various doors. Read more about the different types of door locks here.

For chain locks to work, the window needs to come with curved steel grooves that the lock can latch on so that it can be secured. 

Depending on the window’s type, two grooves are usually attached opposite each other, right on the sashes where it opens.

Hinged Wedge Locks

A hinged wedge lock is usually used for double-hung windows. Typically, it’s placed on the sash, so you would have to push the window’s lock inwards to get it to open; otherwise, it stays closed and locked. 

There are times when this type of lock is placed a little bit higher on the frame. If that happens to be the case, the pane can be opened partially, but it can’t open all the way through unless the lock has been pushed inwards.

Ventilating Locks 

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Ventilating locks are comprised of movable pins that are typically installed either on the window’s frame itself or just slightly above the sash.

 If installed above the frame, it prevents it from being opened all the way. However, when pushed aside, this allows the window to open fully. 

These products are common for windows that you don’t want to open all the way. They are generally installed in a room that needs ventilation, such as bathrooms, basements, and other enclosed spaces. 

Swivel Action Locks

Man unlocking double hung window with swivel action lock

If you’re all about self-locking locks, swivel action styles are definitely for you. This lock doesn’t require any sort of key to secure it. 

These locks are armed with self-locking snibs or “catch” that effectively prevent closed windows from opening, securing them in the process. 

A swivel action lock can work well with double-hung designs. To open a window, it just needs to be swiveled or turned from left to right, releasing the lock in the process.

Smart Locks

Smart lock and smartphone app

Given the latest technological innovations, it has come as no surprise that it has also extended to our locks. Smart locks are electronic, so you don’t need a key to operate them. 

Instead, they operate using entry codes or some sort of authorization from your smartphone app. This allows you to share the code with family, friends, or guests.

These products also typically have sensors you can remotely monitor from your smartphone. So you can keep your window’s security in check even if you are away from your home.

Sliding Window Lock Types

Sliding glass window

True to its name, a sliding lock is typically installed on a sliding window. The locks are installed on the window’s tracks to prevent it from opening. There are two types of mechanisms to keep it in place: it can either be a thumbscrew of sorts or a small lever. If it’s a lever-type sliding lock, simply turn the lever to secure it.

If it’s the thumbscrew type, you just need to twist a wing nut that comes along with it to open or close it. There are also some sliding lock varieties with keyholes, further securing the window.

Horizontal Sliding Locks

A horizontal sliding lock is most commonly seen in the US. It has sashes that can be operated by sliding it from left to right or right to left, and they’re all in a single frame. 

What’s cool about this is that both sides can be opened simultaneously, which is great if you want to maximize airflow in your home. 

Locks For Windows That Slide Up

Slide up window with garden scenery

Top-hung or casement windows look more visually appealing than the other types. However, a common downside to this design is it can be quite hard to keep it fully secure from unwanted intruders. 

There are three locks that you can make use of for casement windows. 

Keyed locks

Key turn lock

Keyed locks can be placed anywhere on the frame if it has a sash where you can install them. You can opt for readily available windows with keyed locks or those without permanent fastening⁠, such as clipped-in keyed locks.

Screw-type locks

This rather inexpensive type of lock can effectively secure a window that slides up. You just need to make sure that it’s screwed tight onto the track.


Rockbolt against white background

This simple type of lock requires a one-inch dowel to fit between a sliding window and its jamb. It may seem rather primitive, but it definitely gets the job done. 

If you aren’t the type who’s into fancy installations or purchases, you can definitely opt to settle on a dowel to keep your slider secure.

Locks For Double-Hung Windows

Close up of double-hung design window with lock

Double-hung windows are quite notorious for being vulnerable to intruders, mainly because of their mechanism. These windows are comprised of two panes placed on top of each other that are typically secured by a half-moon lock. 

Although it appears that half-moon locks should suffice, this is not recommended. In fact, a small knife can easily pry this lock open. 

Here are some of the best locks to secure your double-hung windows.

Andersen’s Double-Hung Locks

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If your top and bottom windows’ sashes are movable, this is the best lock to opt for. They’re designed to hold down both panes, allowing you to close them separately or all simultaneously.

Installation is required for this type of lock, particularly on both sides of the sashes. The device can be flipped through and allows panes to be opened up to 4 inches of ventilation or even get them to fully open, if you prefer.

These types can only work with double-hung designs, though. They’re a bit on the expensive side, but their quality is guaranteed, so they’re definitely worth the investment.

Defender Security U 9929 Double-Hung Locks 

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This lock is made of strong, sturdy steel and is easy to install and operate. It also has a visually appealing antique brass finish. This is most recommended for use on vertically sliding wood windows that are double-hung.

This is installed vertically towards the bottom of the window’s upper sash, effectively creating a wedge between the two sashes that disables the lower sash from being lifted.

Window Wedge

We’ve already briefly described this type of lock above. This is the easiest to install and operate and is highly recommended for homes with small children.

Window wedges have pretty simple mechanisms that wedge the frames shut, making them suitable for double-hung windows. They’re also considered safety locks and can be quite dependable, especially if you have pets and small children around the house.

They allow a certain amount of opening if you want a little bit of ventilation, but they prevent your double-hung designs from opening all the way. This is one of the styles that has been manufactured specifically to keep the inhabitants of the home safe and secure.

Using Lag Screws For Double-Hung Windows

Lag screws

One of the main difficulties in operating locks for double-hung windows is the weight of the upper pane. If a lag screw is installed correctly, it can withstand up to 212 pounds worth of withdrawal, even if only a 5/16-inch shaft is installed, so it can be pretty effective.

This is a cheap but effective option to secure your double-hung designs. Holes are usually drilled on the left and right sides of the sash. The screws are then installed with washers that are recessed. They can usually be tightened with a special key. 

Lag screws also allow you to lock your windows even if they are partially opened, which makes them a convenient choice, especially if you want to have a little bit of ventilation but still want to secure them.

Lock Grades

Close up detail of key style lock on glass door

As a homeowner, you don’t necessarily have to be an expert on lock grades. Still, it does pay to know what kind of ANSI rating you purchase to figure out if they offer the kind of security you require.

This is also a great way to gauge whether these locks are worthy investments, as those with higher grades tend to cost more. We’ve simplified their classifications below. 

What is ANSI?

ANSI stands for American National Standards Institute and is an organization that oversees the standards for systems, processes, products, and services in general. 

Although it’s generally considered a non-profit organization, ANSI ratings provide great insights into the models you plan to purchase and install for your windows at home.

Brass thumb window thumb lock

There are basically three types of lock grades: 1, 2, and 3. Here’s how they differ from each other:

ANSI Grade 1 – This is the highest and strongest lock grade. Commercial heavy-duty security locks fall under this category.

This grade is specifically manufactured to support areas that are considered high-traffic and require maximum security. Although this is commonly used in commercial establishments, it can also be used in residences.

ANSI Grade 2 – This is a lock grade that’s considered high security for residential areas but low security for commercial areas. It can offer superior security in the home but isn’t recommended for commercial use.

ANSI Grade 3 – This is the weakest lock grade that gets the lowest quality rating from ANSI. This is considered as the most basic for residences.

What Is The Safest Lock For Windows?

There is no one-size-fits-all answer for this. We understand that the sheer number of locks available can be overwhelming, but it really all depends on the type of window you have, as well as your needs and preferences.  

First off, consider the type of window you have. Basically, each type requires a specific lock that works for them. See the different types of windows here.

For example, a bolt lock is your most secure option if you have sliding windows. A push lock comes second. You may also use sliding, key, and lock pins.

Locking sliding window

Sliding windows offer more flexibility regarding the lock options you can choose from. If you have double-hung windows, you are also guaranteed that most locking types will work with it, but your best bet is a lag screw.  Not only is it a cheap option, but it’s also one of the most secure ones out there. 

Just pay extra attention to the size of your windowsill, as lag screws don’t work well with particularly large ones. Push locks can also work well with double-hung designs.

How Do You Stop A Window From Opening All The Way?

The best solution for preventing a window from opening is installing a chain lock, commonly used on doors. The window can only extend as far as the chain extends, so you have full control over the amount of opening you want.

For more related content, check out our guide to various types of window blinds.

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