Ring Window and Door Contact Sensor (2nd gen) is the top pick among smart door and window sensors under $20, rated 4.7 stars across 29,608 customer reviews.
Window and Door Contact Sensor (2nd gen)
4.7(29.6K)$14.99
6% OFF
Door and Window Sensor
4.4(6.1K)$16.99$17.99
Contact Sensor
4.4(1.2K)$16.99
SenseGuard DW Gen2
4.1(305)$13.90
DW2-WIFI
3.7(156)$12.90
SNZB-04P ZigBee Door/Window Sensor
3.7(30)$15.90- News by email
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Frequently asked questions
What are the best smart door and window sensors under $20?
Ring Window and Door Contact Sensor (2nd gen), Aqara Door and Window Sensor and SwitchBot Contact Sensor lead our ranking of smart door and window sensors under $20, ordered by customer rating weighted by how many reviews back it. The full list compares 6 products in this price range.
How many smart door and window sensors cost less than $20?
This page tracks 6 smart door and window sensors under $20 from 4 brands, with prices starting at $12.90.
Are these prices up to date?
Prices are re-checked continuously, so every card shows the latest price we have. A product whose price rises above $20 drops off this list on the next update.
Looking for more than $20?
See all the door & window sensors in the catalog, compared side by side on specs, price and rating.