Xiaomi has introduced the Smart Door Lock M40 in China, positioning it as a more affordable alternative to the recently launched M40 Pro while keeping nearly all of the premium features. The key difference between the two is biometric tech: the Pro adds palm vein recognition, whereas the M40 skips that extra method to hit a lower price.
Despite the price cut, the M40 is packed with high-end security and convenience features. It supports multiple unlocking methods, including facial recognition, a fast fingerprint scanner, and PIN codes. Dual integrated cameras provide a wide 190-degree view of your doorway. The primary 3MP camera offers a 175-degree field of view to detect people, while a secondary 128-degree camera focuses on spotting deliveries and other objects.
Inside your home, a 4.98-inch display lets you check who’s at the door without opening it. You can also manage access remotely through the companion app, set temporary codes, and review alerts. Connectivity includes both Bluetooth and Wi‑Fi, and Xiaomi estimates up to around six months of use from a hybrid battery system that combines lithium and AA cells.
Security hardware hasn’t been overlooked. The M40 features a quiet automatic locking mechanism, a C-level lock cylinder, and a built-in security sensor designed to detect tampering.
Pricing in China is set at CNY 3,299 (approximately $464), making it CNY 500 (about $70) cheaper than the M40 Pro. Xiaomi has not yet confirmed international availability or timing.
Key features at a glance:
– Multiple unlock methods: facial recognition, fingerprint, and PIN
– Dual cameras with a combined 190-degree view (3MP primary at 175 degrees; secondary at 128 degrees)
– 4.98-inch indoor screen for at-a-glance visitor checks
– Remote control via the companion app, with Bluetooth and Wi‑Fi connectivity
– Estimated six-month battery life using lithium and AA batteries
– Quiet auto-lock, C-level lock cylinder, and integrated security sensor
– Price in China: CNY 3,299; CNY 500 less than the M40 Pro
For smart-home buyers who don’t need palm vein recognition, the Xiaomi Smart Door Lock M40 delivers a flagship-like experience at a more accessible price.
