A control panel for a door-opening alarm system.


Key takeaways

  • The best window and door opening alarms to purchase are Optex, Safety Technology International, Bunker Hill Security, Arlo, and SimpliSafe.
  • The ButterflyMX video intercom integrates best with a door opening alarm system because it provides additional accessibility and user identification services.
  • Door and window-opening alarms work by utilizing sensors triggered by movement or heat signatures and result in an alarm and/or alert system to users and the authorities


Next to security cameras, door opening alarms are among the most popular tools for building security. They’re easy to install and often inexpensive. However, there are many door alarms on the market, and choosing one can be difficult. That’s where this buyer’s guide comes in.

First, we’ll provide an overview of the best window and door opening alarms to buy. Next, we’ll review the best security system that integrates with a door alarm. Finally, we’ll examine how door alarms work.

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What should you pair a door opening alarm with?

The ButterflyMX video intercom is one of the best upgrades to your security system. It pairs well with door opening alarms for multifamily and commercial properties. While a door alarm can deter crime and notify you of intruders, it does little in the way of access control.

As such, equipping your property with a robust door alarm and access control pairing is a great way to secure your building and tenants further.

The ButterflyMX video intercom system features:

  • Time- and date-stamped entry events. A video recording is stored in the cloud every time a user enters the building.
  • Keyless entry. Users can enter using their mobile phones. All they have to do is tap on the app to open gates and doors.
  • Cloud-based storage. All of your user’s data is stored in the cloud and can be accessed at any time. This allows you to know who exactly is entering your property.
  • Remote access. Residents can provide temporary PIN codes to guests to allow them to enter when they are not home, and you can track all of this through your system’s backend.
  • High-definition video. Our system’s 156° camera lens allows for residents to communicate with visitors face-to-face, and see who else is with them before granting entry. Video can also be streamed from your building’s entry points at any time of day.


The 5 best window and door opening alarms to buy

When upgrading your security system, a door and window opening alarm system is a good choice. However, there are a lot of systems to choose from. Below, we’ve compiled a list of different devices. The biggest variety between them is the special features that they offer.

The five best door and window-opening alarms to buy are:

  1. Optex
  2. Safety Technology International
  3. Bunker Hill Security
  4. Arlo
  5. SimpliSafe


Learn how ButterflyMX works:


1. Optex

Price: $129

The Optex wireless door switch with portable chime is a wireless door announcer that, as the name implies, offers a wireless door opening alarm with sound alerts. Because it’s wireless, this device is extremely easy to install and use out of the box.

Features include:

  • Powered by a 9VDC power adapter.
  • 3 types of chime tones.
  • Integrations with other Optex products
  • A wireless range of 700 feet.


2. Safety Technology International

Price: $71

Security Technology International offers a door alarm ideal for exit and entry doors that are only to be opened in emergencies. As a result, this product is popular for commercial properties.


  • Bright red stop button and a warning label to prevent accidental openings.
  • Key lock that turns off the alarm.
  • Loud siren that emits for three minutes.
  • It’s wireless and runs off a 9VDC battery.
  • Simple to set up and use.


3. Bunker Hill Security

Price: $6.99 for a two-pack.

Bunker Hill Security offers a dual window and door entry alarm that can be utilized for either entryway.


  • Wireless and runs on alkaline batteries.
  • One of the cheapest door opening systems.
  • Dual-purpose for windows and doors.
  • Easy clip-on installation.


4. Arlo

Price: $29.99

Arlo offers an all-in-one sensor with 8 different sensing functions. This can be ideal for both commercial and multifamily properties.


  • This device may offer a door open alarm with delay in case your door or window is left open.
  • A mobile app that can control alarm systems.
  • Sensors in this pack can detect water leaks, ambient light, motion, fires and smoke, and carbon monoxide.
  • Battery-powered.


5. SimpliSafe

Price: $174.99

The SimpliSafe indoor home security system offers an 8-piece package that includes a base station, a keypad control panel, and 6 different sensors.


  • Door opening alarm app and hub to both control and monitor your security devices.
  • Alarm control panel with a panic button.
  • 24/7 professional monitoring that can lead to a fast police response.
  • Does not set off for pets under 60 pounds.


How does a door opening alarm work?

The main way that a door opening alarm works is by having a sensor. Door alarm sensors are usually IR sensors (which is another word for motion sensors). A physical window and door alarm that is located on doors usually connects to a separate device known as the control panel. A door alarm usually connects to the control panel by an RF signal.

Additionally, door alarms can connect to WiFi. This is especially true when they offer features such as remote monitoring and smartphone controls.


An example of a door-opening alarm sensor.


How do door opening sensors work?

When a door or window opens, the door alarm’s sensor is triggered. An IR sensor works by sending infrared light through a perimeter of space. When something in motion disrupts these infrared light beams, the alarm is triggered.

You can also install a door contact sensor. When the door is opened, the button on the sensor releases and alerts you of its open status.

Are door alarms effective?

Door alarms are among the oldest types of security systems. Because they’re so popular, they’re deemed to be effective. A loud, blaring alarm is not the ideal environment to commit a crime, so a door alarm is reasonably effective.

However, it’s important to remember that no security system is 100% foolproof. Door alarms are better seen as a deterrent to intruders. Break-ins can still occur even when you have a door opening alarm system.


Door opening alarm FAQs

Here are answers to your commonly asked questions about door opening alarm systems:


Is there a security system that tells you when a door opens?

Most modern door opening alarms can be programmed to send you an alert when a door opens. Depending on your settings, your door opening alarm can set off an actual, audible alarm to scare off intruders. It can also be programmed to alert the authorities of an unwanted entry event.

Many modern door opening alarms can be set to go off at certain times. For example, if you own a business such as a jewelry store, you can set your door opening alarm to go off outside of business hours.


A fire exit is an example of a door-opening alarm system.


Can you put an alarm on a door?

You can put an alarm on a door by purchasing and installing a door alarm system.


Do door alarms deter burglars?

Certain studies have linked alarms to a drop in burglaries across the country. Door opening alarms are best paired with other security devices to further deter burglars and vandals.


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Nick Manzolillo

I'm a Rhode Island-based writer fascinated with real estate development, the inner workings of the real estate industry, and how real estate and technology blend together.

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