Last updated: August 5, 2021

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Windows are one of the most common ways burglars gain access to other people's homes. To prevent this, it is important to secure your windows in the best possible way. The right window security can help to effectively protect your home from outside dangers and increase the general feeling of security within your own four walls.

We have compared the different window locks and their various mechanisms. We will introduce you to both mechanical and electric window locks and explain how they work. In this article you will also find information about the criteria you can use to choose the perfect window security device for your home or flat.


  • A window lock ensures that breaking open, prising open or smashing windows is made more difficult and, in the best case, prevented. In addition, they can also function as child or pet safety devices.
  • A distinction is made between electrical and mechanical window locks. Electric window locks are alarm systems that primarily act as a deterrent, while mechanical window locks use bolts or additional locks to directly prevent unauthorised opening.
  • Window security devices are often relatively easy to install yourself. There are devices that require drilling into the window frame or wall, but there are also devices that can be installed non-invasively. This can be an advantage in rented flats, for example.

The Best Window Lock: Our Choices

Buying and evaluation criteria for window locking devices

To help you decide which window locking device best suits your needs, we have listed the most important buying criteria here.

In the next paragraph we will explain exactly what these criteria are.

Protection direction

Window locks are most often bought to protect a flat or house from the outside and to prevent burglaries. However, they do not necessarily only protect the outside.

There are some models that integrate the function of a child safety lock at the same time. This ensures that the window cannot be opened without permission, neither from the outside nor from the inside.

Additional locks with a locking function are particularly suitable here. They prevent the window from being opened from both directions, thus providing burglary protection and child safety at the same time.


The dimensions of your window lock depend on how big and how wide your window is and what kind of window it is. There are several different standard sizes in which most windows in Germany are built. Most window locks are based on these sizes.

If you have windows with unusual sizes in your home, for example in an old building, it makes sense to seek advice and, if necessary, buy custom-made products. Additional locks can usually be fitted regardless of the dimensions.

Locking technology

Window locks are available with different locking techniques. With a bolt lock, a bar lock or a swing bolt, a deadbolt is fitted in the window frame or the hinge. This makes it considerably more difficult to break open the window.

There is also the option of securing the window with an additional lock. This works in a similar way to a door lock. Such a lock prevents a smashed or levered lock from being opened simply with the handle.


The material the window lock is made of can also have an impact on security. Most products on the market are made of plastic, but locks made of steel or zinc can withstand burglary attempts longer.

For additional locks as window security, the question of material is less important. Here, however, the choice of material can be more important for aesthetic reasons if you want them to blend in better with the look of the room.


If you want to buy a window lock, it is important to consider the installation beforehand. Especially if you live in a rented flat and do not own your own house.

There are some window locks that require drilling and therefore usually need the consent of the landlord.

Some window locks, both with and without deadbolts, can also often be installed simply, non-invasively. These security devices are usually cheaper, but they are also often easier to detect and identify from the outside.

Pressure resistance

The pressure resistance of a window locking device indicates how high the pressure is that the locking device can withstand when trying to prise it open. The pressure resistance is given in kilograms.

The greater the pressure resistance of a window lock, the greater the effort required to break open the window. Good models have a pressure resistance of about one ton, some even more.

Guide: Frequently asked questions about window locks answered in detail

The topic of window security is quite complex. Therefore, we have compiled the most frequently asked questions in the following section and answered them directly.

What is a window locking device?

Window security refers to various products or mechanisms that can delay or, in the best case, even prevent the prising open or breaking open of a window for as long as possible.


Window locks can protect both the outside and the inside. The most suitable child safety devices are those that make it difficult to open from the inside. (Image source: Rod Long / Unsplash)

There are several different types of window locks. These can differ, for example, in the type of lock. Some work, for example, through bolts attached to the window, others through additional locks.

There are also window locks that lock mechanically on the one hand and those that trigger an electronic alarm on the other.

What types of window locks are there?

A distinction is usually made between electronic and mechanical window locks. They differ both in the way they work and often in the price category.

Mechanical window locks are basically all types of additional locks and bolts that can be attached to the window.

Even very old windows can usually be easily retrofitted with mechanical window locks. This prevents the window from being prised open or greatly prolongs the time it takes to break in.

Electronic window security devices are basically alarm systems that go off when the window is prised open or smashed. They have the disadvantage that an electronic window security system does not in itself prolong or prevent the burglary process. However, it can act as a deterrent and, if necessary, attract attention.

What does a window locking device cost?

The price of a window lock depends on a number of factors, such as the dimensions of the window or the type of lock. We have listed the price ranges of various products here to give you an overview of the costs.

Products available price class
Window security with bolt approx. 20 to 120 euros
Window security with additional lock approx. 20 to 80 euros
Electric window security approx. 25 to 200 euros

Electronic window locks are therefore often more expensive than mechanical window locks. However, inexpensive ones can be found in every category. Prices also vary greatly depending on the manufacturer and brand.

How do I install a window locking device?

In most cases, window locks can be installed by the user. Therefore, the procedures are often very simple and in many cases you do not need more than a screwdriver. The correct way to install a window locking device depends on the type of window locking device.

Telescopic bars, for example, are mounted on the wall next to the window, which has the advantage that the window itself does not have to be damaged.

Other products, such as an additional lock, usually require drilling into the window. This can be complicated. It is important to test beforehand whether the window can be opened and closed properly and, if necessary, mistakes should be corrected. It is also important to ensure that the hole is drilled to the correct depth and to avoid drilling through the window frame.

To which windows can I attach window locks?

Basically, window locks can be fitted to all conventional window types. However, which window security device is best suited for which window depends on the type of window.

Electric window locks that work via an alarm system can be fitted to all windows and also to balcony doors. Additional locks can also be easily attached to any window frame. This is more difficult with some types of deadbolts, as they are sometimes very dependent on the window opening and the size of the hinges.


Since burglars often use windows to gain access to their homes, it makes sense to protect your house or flat with window locks. You can choose between different locking mechanisms and between mechanical and electric window locks that work with an alarm.

The large selection on the market makes it possible to find the right window security device for your own needs and living conditions. Some models also integrate a child safety lock, and thus also protect against unauthorised opening from the inside and the possible accidents that go along with it. They are therefore ideal for strengthening the sense of security in your own home.

Image source: Paul Barlow / Pixabay

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