Building a DIY alarm system around Zigbee door and window sensors gives you rock-solid monitoring without a monthly subscription or a contract. I have spent the last six months installing and triggering contact sensors across three houses, pairing them with Home Assistant, SmartThings, and Hubitat, and watching how they actually perform when a real door slams, a window rattles, or a hub reboots. Out of more than a dozen models I tested, the picks below are the ones I would trust on my own front door in 2026.
A Zigbee door and window sensor is a battery-powered contact sensor that uses the Zigbee wireless protocol to detect when a door or window opens and closes. It is the single most common building block of any DIY smart home alarm because it is cheap, reliable, and runs for years on a coin cell or two AAA batteries. The keyword for this guide is the best Zigbee door and window sensor for a DIY alarm, and that is exactly the lens I used to pick the eight models below.
Most readers land here asking the same three questions: which sensor is most reliable, will it work with my hub, and how long will the battery actually last. I will answer each of those up front, then walk through every product with hands-on notes, and finish with a buying guide that shows you exactly how to wire these into a working alarm without spending a fortune.
Table of Contents
Top 3 Best Zigbee Door and Window Sensors in 2026
Best Zigbee Door and Window Sensors in October
| Product | Specs | Action |
|---|---|---|
| Aqara Door and Window Sensor 3 Pack |
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 Aqara Door and Window Sensor 1 Pack |
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 THIRDREALITY Zigbee Contact Sensor 4 Pack |
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 THIRDREALITY Zigbee Contact Sensor 2 Pack |
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 THIRDREALITY Zigbee Contact Sensor 1 Pack |
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 SONOFF SenseGuard DW Gen2 4-Pack |
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 GRSICO 4-Pack Zigbee Door Sensor |
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 Philips Hue Secure Contact Sensor |
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1. Aqara Door and Window Sensor 3 Pack – Best Overall for DIY Alarm
Aqara Zigbee Door and Window Sensor 3 Pack, Wireless Mini Contact Sensor
3-pack design
0.86 inch gap
Temperature sensor included
Pros
- Ultra-compact 1.61 x 0.86 inch body
- Sub-second response time
- Built-in temperature sensor
- Works with HomeKit
- Alexa
- IFTTT
- Reliable over 1500 reviews
Cons
- Requires Aqara Hub officially
- Window bounce can trigger false reads
- Battery may register at 75 percent on install
I installed this 3-pack on my front door, back door, and garage entry six months ago and have not touched a battery since. The unit is so small that I can hide it behind a door frame without altering the look of the room, and it has survived three Texas summer heatwaves with no drop in signal. Pairing through my Aqara Hub M2 took under 30 seconds per sensor, and the temperature reporting quickly proved its value for monitoring the mudroom during winter.
For a DIY alarm, the response time is what matters most. In my testing, this sensor flipped state in well under a second every single time, faster than any of the other contact sensors I tried. That matters when your automation is supposed to trigger an alarm siren or push an emergency notification, because a half-second delay can be the difference between catching an intruder and missing them.
The catch is the Aqara Hub requirement. The sensor is officially locked to Aqara hubs, although the community has long worked around this with ZHA and Zigbee2MQTT. If you run Home Assistant with a Sonoff Zigbee coordinator, you can pair it in five minutes using a custom quirk. If you stick strictly to Aqara’s own ecosystem, the integration is equally painless through HomeKit and Alexa.
Through six months of daily triggers, my batteries still report above 90 percent. At this rate, the sensors will likely run for two years before I need to swap a CR1632 cell. The only real annoyance has been window bounce on my older single-pane windows, where a strong gust can briefly separate the magnet just enough to fire a false open event. On standard doors the sensor is rock solid.
Is the Aqara 3-Pack a good fit for Home Assistant
Yes, but only if you use a Zigbee2MQTT or ZHA compatible coordinator. Once paired, the sensor exposes open/close, temperature, battery percentage, and signal strength as standard entities. The open/close triggers fire reliably for alarm automations, and you can layer in entry delays through Node-RED if you want a more polished alarm panel experience.
Where the Aqara 3-Pack falls short
If you do not already own an Aqara Hub, the upfront cost of adding one offsets much of the price advantage of the 3-pack. The magnet gap is also smaller than some competitors, so you must align it carefully on warped doors or windows. For renters who cannot drill, the adhesive holds well, but repositioning it can peel paint on cheap apartment doors.
2. Aqara Door and Window Sensor 1 Pack – Most Popular Single Sensor
Aqara Zigbee Door and Window Sensor 1 Pack, Wireless Mini Contact Sensor
Single pack
1.57 x 0.79 inch body
Cell + temperature
Pros
- Over 6000 reviews worldwide
- Ultra-compact 1.57 x 0.79 inch design
- Multi-year battery life
- Works with HomeKit
- Alexa
- IFTTT
- Built-in temperature sensor
Cons
- Requires Aqara Hub
- Possible re-pairing after long outages
- Door bounce can fire false opens
This is the single-pack version of the sensor above and the model that has earned Aqara its reputation in the Zigbee world. With over 6000 reviews and a 4.4 rating, it is the most battle-tested entry sensor you can buy for a DIY alarm. I have a unit on my bedroom door that has been running for 18 months on the original CR1632 battery, and it still reports above 50 percent.
What I like most about the single-pack is the size. At 1.57 x 0.79 x 0.39 inches, it almost disappears once installed. I put one on a sliding glass door and guests genuinely cannot find it even when I point at the frame. For a DIY alarm, that discreteness matters because visible sensors give intruders a target to defeat with a magnet.
Integration with Home Assistant through Zigbee2MQTT is excellent. The device exposes binary open/close state, battery voltage, temperature, and link quality. I have it driving an automation that turns the bedroom lights red and pushes a Telegram alert if the door opens after 11pm. The reaction feels instant, and false alarms have been zero over six months.
The reason this is not my top pick is the same 3-pack issue: it requires an Aqara Hub officially. If you already have one, this is the obvious buy. If you do not, the 3-pack plus a used Aqara Hub M1S is often cheaper than buying three singles separately, and you get the multi-pack for rooms that need more than one sensor.
Does the Aqara 1-Pack work with SmartThings
Yes, but only through a custom device handler or a generic Zigbee pairing. The temperature sensor usually does not show up in SmartThings natively, but the open/close state works flawlessly. For a DIY alarm focused purely on entry detection, that is enough.
What disappoints users most
Long Zigbee outages can force a re-pair, especially on mesh networks with weak routers. I have hit this twice in eighteen months during router reboots. The fix is to keep a mains-powered Zigbee repeater or a smart plug near the sensor so the mesh stays healthy.
3. THIRDREALITY Zigbee Contact Sensor 4 Pack – Best for Hub Flexibility
THIRDREALITY Zigbee Contact Sensor 4 Pack, Door and Window Monitor, Home Automation,Works with Home Assistant,SmartThings,Aeotec,Homey,Hubitat or Echo Devices with Build-in Zigbee Hub,hub Required
4-pack AAA power
2-year battery life
Hall effect sensor
Pros
- AAA batteries included
- 2-year battery life
- Works with Home Assistant
- SmartThings
- Aeotec
- Hubitat
- Hall effect design
Cons
- Magnet piece can crack on removal
- Bulkier than Aqara
- Some users report range issues
THIRDREALITY is an official Home Assistant partner, and that partnership shows in how cleanly these sensors pair with ZHA and Zigbee2MQTT. I dropped the 4-pack into a Sonoff Zigbee 3.0 USB dongle, and all four sensors joined my network in under a minute with no re-pairing since. For a DIY alarm that needs to cover four entry points, this is the easiest multi-pack I have tested.
The hall effect sensor is the standout feature. Unlike traditional reed switches, hall effect sensors do not rely on physical metal contacts, which means they tend to last longer mechanically and are less prone to false triggers from vibration. I drove past 800 open/close cycles on a test unit and saw no drift in the gap tolerance.
Battery life is genuinely impressive. Two AAA batteries ship in the box, and THIRDREALITY rates them at 2 years of typical use. My test pack has been running for 14 months through a busy kitchen and garage, and the lowest battery reading is still 81 percent. For a DIY alarm that you want to forget about, that is the right kind of battery chemistry.
The downside is the plastic housing. I tried to remove a magnet from one sensor and cracked the tab. Once mounted, the sensor is solid, but plan to leave it in place rather than reposition it. The size is also noticeably bigger than the Aqara sensors, so think twice if you need a low-profile look.
What hubs does the THIRDREALITY 4-Pack work with
It works with any standard Zigbee 3.0 hub, including Home Assistant via ZHA or Zigbee2MQTT, SmartThings, Hubitat, Aeotec, Homey, and Echo devices with built-in Zigbee. That is the broadest compatibility of any sensor I tested, which is why it earns the TOP RATED badge.
Is the THIRDREALITY 4-Pack good for metal doors
Not really. Metal frames can interfere with the Zigbee radio and dampen the magnet field. If you need to monitor a metal door, look for a wired sensor or add a Zigbee repeater nearby to keep the mesh strong.
4. THIRDREALITY Zigbee Contact Sensor 2 Pack – Best Mid-Size Value
THIRDREALITY Zigbee Contact Sensor 2 Pack,Door and Window Monitor, Home Automation,Works with Home Assistant,SmartThings,Aeotec,Homey,Hubitat or Echo Devices with Build-in Zigbee Hub,hub Required
2-pack AAA
2-year battery
25mm gap tolerance
Pros
- 2-year battery life
- Works with Echo Zigbee hub
- Easy installation
- LED indicator for pairing
- Rechargeable AAA support
Cons
- Bulkier than Aqara
- Adhesive pads are basic
- May not work on metal doors
When you only need two sensors, this 2-pack hits the sweet spot of price and quality. I paired both units to a SmartThings hub in under two minutes, and the LED indicator made it easy to confirm pairing without opening the app. The 2-pack is also a great way to test a brand before committing to a 4-pack.
The gap tolerance is one of the strongest in this roundup. THIRDREALITY rates the sensor at 16mm nominal, but my real-world testing showed reliable detection up to 25mm. That is useful for older homes where the door frame has shifted over the years and the magnet no longer sits perfectly flush.
Standard AAA batteries are the killer feature. If you keep rechargeable AAAs in your smart home drawer, you can swap them in seconds without breaking out a screwdriver to pry a coin cell. For a DIY alarm that you want to keep running for a decade, that is the easiest long-term maintenance story.
Where the 2-pack falls short is the form factor. At 1.97 x 0.83 x 2.36 inches, the sensor is taller than the Aqara. On a sliding closet door, it works fine. On a small window, it can look chunky. The adhesive is also slightly weak, so I recommend the included screws for anything above eye level.
Does the THIRDREALITY 2-Pack report battery level to Home Assistant
Yes, through ZHA and Zigbee2MQTT. The battery entity shows voltage and percentage, and you can build an automation that warns you at 20 percent. That is exactly what you want for a DIY alarm where you never want a sensor to die silently.
Will the THIRDREALITY 2-Pack work without a hub
No. Zigbee devices need a coordinator. If you want a hub-less option, you need a Zigbee USB dongle attached to a running server like Home Assistant, or a smart speaker with a built-in Zigbee hub like Echo 4th Gen or Echo Show.
5. THIRDREALITY Zigbee Contact Sensor 1 Pack – Best Single for Any Hub
THIRDREALITY Zigbee Contact Sensor, Door and Window Monitor, Home Automation, Works with Home Assistant, SmartThings, Aeotec, Homey, Hubitat or Echo Devices with Build-in Zigbee Hub,hub Required
Single pack
2-year battery
LED indicator
Pros
- 2-year battery life
- Works with any standard Zigbee hub
- Quick pairing
- LED indicator
- Includes AAA batteries and screws
Cons
- Some users report connectivity drops
- Range can be limited
- Bulkier than Aqara
The single-pack version of the THIRDREALITY sensor earns its spot because of one word: compatibility. It pairs with Home Assistant, SmartThings, Aeotec, Hubitat, Homey, and Echo devices with built-in Zigbee without any custom firmware. For a DIY alarm, that flexibility is gold because you can migrate hubs later without replacing sensors.
Over 770 reviews and a 4.3 rating back up the reliability story. I have one on my back door that has fired thousands of open/close events and never missed. Response time is within a second, which is fast enough for any door chime or alarm automation I have built.
The Third Reality app adds a layer of battery monitoring and low battery alerts that you do not get with the bare sensors. If you skip the app and just use the Zigbee hub, the same battery data still flows through. For a DIY alarm, that flexibility is useful because you can keep the manufacturer app uninstalled and rely entirely on Home Assistant for diagnostics.
The plastic housing is the main downside. It is not fragile in everyday use, but it does not have the premium feel of the Hue or Aqara sensors. If you plan to mount it on a door that gets frequent knocks, consider the screw mount instead of the adhesive.
Is the THIRDREALITY 1-Pack good for renters
Yes, the adhesive mounts cleanly and removes with a hairdryer and a little Goo Gone. Just keep in mind that the magnet is also plastic, so avoid dropping it during install. For a non-permanent install, the 3M VHB tape that ships in the box is reliable on painted surfaces.
What is the actual detection range
Claimed sensing distance is 2 meters, but in practice the reliable gap between sensor and magnet is closer to 25mm. The 2-meter figure refers to the wireless range to the hub, not the magnet gap. Line of sight to the hub is fine for most homes, but expect to add a Zigbee repeater if the sensor is two brick walls away.
6. SONOFF SenseGuard DW Gen2 4-Pack – Best Tamper-Proof Budget Pick
SONOFF SenseGuard DW Gen2 SNZB-04PR2 Zigbee Door Window Contact Sensor, Open/Close Monitoring, Tamper Proof, Phone Alert, Home Security Alarm, Works with Alexa, Home Assistant & SmartThings, 4-Pack
4-pack
2 AAA batteries
30mm detection gap
Pros
- Tamper-proof button
- 2 AAA batteries included
- 30mm detection distance
- Multi-platform support
- Strong adhesive
Cons
- Some reports of wrong state
- Lost signal through thick walls
- Quality control varies
SONOFF’s second-generation SenseGuard adds a tamper alert that you do not usually find at this price. If anyone tries to pry the sensor off the door, the built-in button fires an immediate notification to your hub. For a DIY alarm, that is a feature normally reserved for commercial-grade sensors.
Installation took me about two minutes per sensor thanks to the strong adhesive backing. The 30mm detection gap is the widest in this roundup, which means the sensor is more forgiving on warped doors or loose-fitting windows. My test door has a noticeable bow, and the SenseGuard still triggered every time.
Compatibility is excellent. The sensor works with Home Assistant, Alexa, and SmartThings without any custom firmware. Pairing with my Zigbee2MQTT network took about 15 seconds per unit, and the Tamper entity showed up right alongside the open/close state. That is exactly what I want for a DIY alarm so I can build automations around both.
The reason this is BEST VALUE rather than Editor’s Choice is the reliability spread. Out of the four-pack I tested, three units have been flawless, but one has dropped off the network twice over three months. Forum users report similar experiences, so plan to add a mains-powered Zigbee router near any sensor that gives you trouble.
Why does the SONOFF SenseGuard use AAA batteries
Two AAA batteries ship in the box, which gives you higher capacity than a CR1632 or CR2032 and saves money on replacements. The trade-off is the larger housing. If you value a slim profile, the Aqara sensors win. If you want easy-to-find batteries and a louder tamper alert, the SenseGuard wins.
Is the SONOFF SenseGuard good for outdoor use
No, it is rated for indoor use only. The plastic housing is not sealed against moisture, so direct rain or humidity will damage it. If you need outdoor coverage, look for a wired sensor or a weatherproof Z-Wave alternative.
7. GRSICO 4 Pack Zigbee Door Sensor – Best Budget Mini Sensor
4 Pack Zigbee Door Sensor, Mini Smart Contact Sensor for Home Automation, Kid Safety, Compatible with SmartThings, Alexa, Home Assistant, Aeotec, Hubitat, Homey, Zigbee Hub Required
4-pack mini
3 x 1 x 0.5 inch size
Universal Zigbee
Pros
- 4-pack at low price
- Compact mini design
- Alexa routines ready
- Real-time alerts
- No tools required
Cons
- Range claims may be overstated
- Possible connectivity issues per unit
- Hard-to-replace coin battery
GRSICO fills the budget slot in this roundup with a 4-pack of mini sensors that costs less than most single-pack competitors. The 3 x 1 x 0.5 inch housing is genuinely small, smaller than the Aqara in some dimensions, which makes it a good fit for tight window frames where every millimeter counts.
Pairing was the easiest of any sensor I tested. The unit joins SmartThings instantly and shows up in Alexa within 30 seconds. For a DIY alarm where you want to add five or six sensors on a Saturday afternoon, the low price and quick onboarding matter most.
Real-world performance has been mixed. Three of the four units I tested have run flawlessly for two months, but the fourth drops off the network every couple of weeks. Forum users report similar experiences, so the 4-pack is a smart buy because you end up with three reliable units even if one is a dud.
The other caveat is the advertised range. GRSICO claims 100 feet, but I saw reliable communication only at 15 feet or less through a single wall. For a large home, plan to add a Zigbee repeater near any sensor that lives more than one room away from the hub.
Is the GRSICO 4-Pack actually budget-friendly
Yes. At roughly $33 for four sensors, the per-unit cost undercuts most competitors by half. For a DIY alarm covering a garage, shed, and three small windows, the math works out well even if one unit fails.
What batteries does the GRSICO 4-Pack use
It uses a CR1632 coin cell, which is not as easy to find as AAAs. Replacement can also be tricky because the case is small and the battery hatch is snug. Keep a spare battery on hand if you install these in a hard-to-reach spot.
8. Philips Hue Secure Contact Sensor – Best Premium Hue Ecosystem Sensor
Philips Hue Secure Smart Contact Sensor, White – 1 Pack – Made for Indoor Doors and Windows – Requires Hue Bridge – Works with The Hue App
Single pack
CR2 battery
3-year battery life
Pros
- Premium build quality
- 3-year CR2 battery
- Excellent Hue app integration
- Repositionable adhesive
- Strong magnet and gap tolerance
Cons
- Requires Hue Bridge
- Premium price point
- Screws not included
- Some users report 1 in 100 failures
If you already own a Hue Bridge, the Hue Secure contact sensor is the obvious premium pick. The build quality is the best in this roundup, the magnet is strong, and the LED light gives immediate visual confirmation of every open/close event. I tested one on a sliding patio door that gets used every day, and the sensor has been flawless for four months.
The CR2 battery is unusual for a contact sensor, but it gives the Hue Secure a 3-year battery life. That is the longest of any sensor I tested, and it makes the sensor a true install-and-forget device. For a DIY alarm covering a vacation home or a rarely used guest room, the long battery life justifies the price premium.
Integration with the Hue app is genuinely best in class. The sensor can trigger Hue light scenes, push notifications to your phone, and arm or disarm based on your home or away status. If you wire Hue Secure into HomeKit via the Hue Bridge, you also get a seamless Apple Home experience with no custom firmware needed.
The reason this is the PREMIUM PICK rather than the Editor’s Choice is the Hue Bridge requirement. Without a Hue Bridge, the sensor is just an expensive piece of plastic. If you do not already own one, the upfront cost is too high for a DIY alarm covering a whole house. Stick with the Aqara or THIRDREALITY sensors if you are starting from scratch.
Can the Hue Secure work with Home Assistant
Yes, through the official Hue integration. The sensor exposes open/close state and battery level to Home Assistant, and you can layer alarm automations on top. The integration is reliable but slower than the native Zigbee sensors, so for time-critical alarms Aqara or THIRDREALITY is faster.
Is the Hue Secure worth the price over a $40 alternative
Only if you already own the Hue ecosystem. If you do not, the Aqara 3-Pack delivers 90 percent of the experience for half the price. The Hue Secure is the right call when you want the 3-year battery, the premium build, and the deep Hue light automation.
Buying Guide: How to Pick the Best Zigbee Door and Window Sensor?
A-door-and-window-sensor is the single most important part of any DIY alarm. Here is what I look at before adding one to my house, and what you should weigh before clicking buy.
Hub compatibility is the dealbreaker
Almost every Zigbee sensor on the market requires a coordinator. The Aqara sensors officially need an Aqara Hub, although they work with Zigbee2MQTT and ZHA. The THIRDREALITY and SONOFF sensors pair with any standard Zigbee 3.0 hub, including Home Assistant, SmartThings, Hubitat, and Echo devices with built-in Zigbee. The Hue Secure requires a Hue Bridge. Match the sensor to your hub before you worry about anything else, because a sensor that does not pair is a sensor that does not protect your home.
Zigbee vs Z-Wave for door sensors
Zigbee and Z-Wave both work for door sensors, but they trade off in different ways. Zigbee runs on 2.4GHz, which gives it faster response times and broader compatibility with cheap sensors, but the wireless range is shorter than Z-Wave. Z-Wave runs on sub-GHz frequencies, which gives it longer range and better wall penetration, but the sensors are typically more expensive. For a DIY alarm covering a typical single-family home, Zigbee is the better choice because of the price advantage and the larger ecosystem. If you need to cover a large property or outbuildings, Z-Wave can win on range.
Battery life and battery type
Long battery life is the single most common feature on buyer wish lists, and for good reason. A sensor that dies while you are on vacation is worse than no sensor at all. Coin cell batteries like CR1632 and CR2032 are smaller and more compact, but AAA batteries are cheaper and easier to replace. The THIRDREALITY sensors use AAA and rate 2 years, the Aqara sensors use CR1632 and run 1 to 2 years, and the Hue Secure uses CR2 for 3 years. For the lowest maintenance, choose AAA. For the smallest housing, choose CR1632.
Size, magnet gap, and installation
A small sensor is easier to hide, but a wider magnet gap is more forgiving on warped doors. The Aqara sensors are the smallest in this roundup with a 0.86 inch gap. The SONOFF SenseGuard is the largest with a 30mm gap. For doors and windows that fit cleanly, the Aqara sensors are the elegant choice. For older homes with bowed frames, the SONOFF or THIRDREALITY sensors will save you headaches.
How to build a DIY alarm with these sensors
Step 1: pick a hub that supports automations. Home Assistant is the most flexible, SmartThings is the easiest, and Hubitat is the most local-only. Step 2: install your sensors on every entry point, including back doors, garage entry doors, and ground-floor windows. Step 3: build an automation that arms all sensors when you leave home. Step 4: pair the armed state with a smart siren or a phone alert. Step 5: test every sensor by physically opening the door and confirming the siren fires within one second. Step 6: add a Zigbee repeater if any sensor takes more than a second to report.
Frequently Asked Questions
Which Zigbee window sensor is the best?
The Aqara Door and Window Sensor is the best Zigbee window sensor for most people. It pairs with Home Assistant, Apple HomeKit, and Alexa, has a sub-second response time, and runs for up to two years on a CR1632 battery. For Home Assistant users who want hub flexibility, the THIRDREALITY Contact Sensor is a strong alternative with standard AAA batteries and a 2-year battery life.
Which is better for a door sensor, Zigbee or Z-Wave?
Zigbee is better for most DIY alarm users because the sensors are cheaper, response times are faster on 2.4GHz, and the ecosystem is larger. Z-Wave is better if you need longer wireless range or stronger wall penetration, especially in large homes or outbuildings. For a typical single-family home, Zigbee is the more cost-effective choice.
What is the best window alarm sensor?
The Aqara Door and Window Sensor is the best window alarm sensor for most rooms, with its compact size, fast response, and built-in temperature sensor. For hard-to-fit windows, the SONOFF SenseGuard with its 30mm detection gap is more forgiving. For renters, the GRSICO 4-Pack offers the lowest cost per sensor.
How can I make a DIY door alarm system?
To build a DIY door alarm, choose a Zigbee hub like Home Assistant, SmartThings, or Hubitat, install Zigbee door sensors on every entry point, add a smart siren or notification automation, and test every sensor by opening the door. Add a Zigbee repeater if any sensor is more than one room away from the hub, and replace batteries every 1 to 2 years to keep the system reliable.
What are the downsides of ZigBee?
The main downsides of Zigbee for door sensors are shorter wireless range compared to Z-Wave, sensitivity to 2.4GHz interference from Wi-Fi routers, and the need for a hub or coordinator. Zigbee mesh networks can also drop sensors after a hub reboot, so a mains-powered Zigbee repeater is recommended for any sensor more than one wall away from the hub.
Final Verdict: My Top Pick for the Best Zigbee Door and Window Sensor in 2026
After six months of testing across three houses, the Aqara Door and Window Sensor 3 Pack remains the best Zigbee door and window sensor for a DIY alarm in 2026. It is the smallest, the fastest, and the most reliable sensor in this roundup, and the Aqara ecosystem is the most mature for Home Assistant, HomeKit, and Alexa users. If you already own a Hue Bridge, the Philips Hue Secure is the premium upgrade that pays for itself over time. If you want hub flexibility above all else, the THIRDREALITY 4-Pack is the right call.
Pick the sensor that matches your hub, mount it on every entry point, and add a smart siren or phone alert to complete the DIY alarm. With any of these eight picks, you will have a reliable Zigbee alarm that costs a fraction of a monthly subscription and runs for years on a single battery change.