We may receive a commission on purchases made from links.

When constructing a smart home, the usual bunch of gadgets most people consider includes smart screens, lights, plugs, and other such gadgets that can automate tasks around the house. Most of these gadgets are useful, and some can even save you a ton of time and money. However, more often than not, the savings start to compound over the long run, since many smart home tech devices can be rather expensive. This may deter many folks from dipping their toes into the world of smart home gadgets. If you were on the fence due to higher costs, you will be surprised to know that there are several gadgets you can purchase for under $10 to make your home smarter.

We’ve made a list of five sensors under $10 that give a good introduction to the world of smart home tech. We’ve included a wide range of gadgets to meet various needs around the house. From door and window sensors that can trigger an alarm when there’s an intruder to water leak detection that could prevent a major mishap, there are a surprising number of smart home tech products that you can buy without making a dent in your wallet. All the products on this list either perform a specific function when the sensor detects an anomaly, such as sounding an alarm, or relay a notification to a connected device, such as a smartphone.

You’ve probably heard of smart locks for your main door, which allow you to enter a PIN or your fingerprint to unlock your door. However, door and window sensors may be among the smart home gadgets you didn’t know existed. The Plojop security door and window alarm can sound an alarm every time there’s an intruder. These sensors come in pairs and attach to either side of the door or window. Each sensor has strong magnets. When a door or window is closed, the magnets attract each other, completing the circuit. However, if someone opens the door, the magnets detach, breaking the circuit. This triggers the built-in alarm, alerting you to the intruders.

You can also use the sensors to know whenever your child or pet enters or exits a room. Since these are independent sensors that don’t rely on an internet connection or other external factors, you can install them anywhere in the house. You get four pairs in a pack, which makes this an excellent value proposition. As per users, the built-in alarm is loud, so you can hear it from a distance. That said, reviewers report that the build quality is somewhat flimsy, so you may want to install the sensors with care. If you’re willing to spend slightly more than the $9.78 asking price, you can get a door sensor that can also notify you on your smartphone when a door or window is opened. That’s a more practical solution for those who aren’t home most of the time.

The Inkbird digital hygrometer is one of the smartest gadgets on this list, and the primary reason for that is that it connects to your smartphone via Bluetooth. You don’t have to be physically near the device to view the temperature or other data displayed on it. It tracks your home’s temperature and humidity and displays it on the built-in seven-segment screen. Thanks to Bluetooth connectivity, you can also view these stats on your smartphone — as long as you’re within Bluetooth range. We wish there were Wi-Fi connectivity for remote tracking, even when you’re not at home, but given the $6.99 price, we can’t complain too much.

For those wondering, there are several use cases for the Inkbird digital hygrometer around the house. The best example is if you’re growing plants. Installing the hygrometer lets you track condensation and VPD curves, which are required for an ideal environment for growing certain plants. You can also use it in your kid’s bedroom to ensure the right temperature and humidity are maintained. Some other areas you can use this gadget are a wine cellar, a poultry farm, and a bathroom. The device can store data for 300 days, which you can export as a CSV file. Moreover, you can set upper or lower limits in the app, and you will be notified whenever the temperature or humidity goes out of range.

Once you add NFC tags around the house, there’s definitely no going back. That’s how powerful they are. Moreover, the Innohhustle NFC tags are super cheap at just $9 for a pack of 50, which is effectively less than 20 cents per tag. For those wondering, these NFC tags are essentially stickers that can store certain data to activate set functions when they’re scanned. For instance, you can program an NFC tag to trigger the Do Not Disturb mode on your phone. Once you do that, every time you tap your phone on the tag, DND will be activated. Tap once again, and DND will be deactivated. This saves you time and the effort of manually turning the setting on and off. While this is a simple example, you can use NFC tags for more complex purposes.

Stick one on your work desk and program it to mute all notifications except those from your colleagues. You can also have one in your car that does the exact reverse: mutes all work notifications and only filters personal messages and emails. This way, you can scan it as soon as you enter your car to drive back home. Some other use cases include playing music as soon as you enter the shower, opening a certain app at a specific location, or even triggering iPhone shortcuts or automations. These tags from Innohhustle are reprogrammable, so you can rewrite them multiple times if you don’t use an older tag anymore for its initial intended purpose.

Overflowing or leaking taps at home can be a massive hazard, as they can lead to flooding or even electrocution. If you have a big house, you cannot keep track of all the taps to see if they’re malfunctioning. That’s where a water leak detector sensor comes in handy. These tiny gadgets can be installed in your bathroom, kitchen, basement, or even backyard to detect water leaks from taps or pipes. The Metak water leak detector sensor costs just $10 and can be a potential life-saver. Once installed, the sensor sounds an alarm if it detects leakage. According to a user, the alarm could have been louder, as they could only hear it one floor above. Despite that, it saved their basement from potential flooding. Another user reported that one of the alarms wasn’t as loud as the other, so it could be that certain units have less-powerful speakers.

If you’re willing to shell out more money, you can pick up a more sophisticated water leak sensor that can even send notifications to your phone when it detects a leak. However, if you’re going to use multiple sensors around the house, Wi-Fi-enabled sensors can get quite expensive. Apart from pipes and taps, you can also install the sensor near washing machines, dishwashers, and even water dispensers. This way, you’ll know when to clean stagnant water, since it can get dangerous if you have kids running around the house.

Smart lights aren’t new. People have been using them in their homes to change colors, brightness levels, and set custom routines that turn the lights on and off at a set interval for a long time. The same applies to motion sensor lights that turn on as soon as you enter a room. However, these lights are generally expensive, and replacing existing lights means that all the bulbs you’re presently using will have to be thrown into a drawer. Unless, of course, you get the Cysfetena PIR motion sensor switch. As the name suggests, this is a smart switch that adds motion detection capabilities to existing USB lights. The best use case of this gadget is with strip lights or other RGB lighting that connects to a USB power source.

If you’re wondering how it works, first connect your light source to the PIR motion sensor switch, then connect the switch to a power source. As soon as the motion sensor detects movement, it turns the switch on, and your lights come on. As per the brand, the detection range is between 5 and 7 meters, and the IR rays ensure the lights turn on only when a human is detected. You can also set the duration for which the light remains on once it detects motion. For a sensor that costs just $9, the features are definitely impressive. If your lights use a DC connector instead of USB, you can pick up the Sensky PIR motion-activated sensor switch instead.