Smart Lock - Mortise Lock with Handle (S821)

The S821 smart lock is a slim mortise handle that opens five ways: fingerprint, code, IC card, the Tuya app and a mechanical key. It joins your Wi-Fi directly, so there is no gateway to buy.

• Five ways into the door
• Codes you can take back
• No gateway to buy
• Fitting an S821 smart lock
• Straightforward, if the mortise matches

Codes can be temporary, so a guest or a contractor gets one that stops working on its own, and the app keeps the record of who opened the door and when. It holds 300 users, nine of them administrators.

The keypad is backlit, which matters at a front door at night. Fingerprints read at any angle and match in 0.6 seconds. There is an electronic anti-lock for when you want the door dead from the inside, and a USB Type-C port on the outside panel takes a power bank if the batteries run flat while you are out.

It fits doors 38 to 55 mm thick on a 5050 mortise, 22 x 160 mm, left or right handed. Black is what we stock; red bronze and silver are available to order.

Five ways into the door

The S821 smart lock opens by fingerprint, code, IC card, the Tuya app or a mechanical key. The semiconductor reader sits in the ring at the base of the handle, reads at any angle and matches a print in 0.6 seconds, so the hand already reaching for the door is the hand that opens it.

The keypad is backlit, which sounds like a small thing until you have stood at an unlit front door trying to find the digits. Codes are six to eight digits.

Codes you can take back

Codes can be temporary, so a guest or a contractor gets one that stops working on its own without you having to remember to remove it. The app keeps the record of who opened the door and when, and the lock holds 300 users, nine of them administrators.

There is an electronic anti-lock for when you want the door dead from the inside overnight.

No gateway to buy

The S821 smart lock joins your Wi-Fi directly. There is no hub, no bridge and no second box, which is worth counting into the price when comparing it with a Bluetooth lock that needs one to work from anywhere.

Fitting an S821 smart lock

It takes doors 38 to 55 mm thick on a 5050 mortise at 22 x 160 mm, handed left or right, with a 270 x 65 mm panel in aluminium alloy. Four AA alkaline cells run it and a 5 V USB Type-C port on the outside panel takes a power bank if they go flat while you are out.

It works from -25 to 60 degrees C, ships with English firmware and nine other languages available. Black is what we stock; red bronze and silver can be ordered, so tell us the finish before you pay.

Straightforward, if the mortise matches

Doors 38 to 55 mm on a 5050 mortise at 22 x 160 mm, handed either way. Nothing else about this one is complicated: Wi-Fi is built in, there is no hub, and the keypad lights up at night, which matters more on a front door than the spec sheet suggests.

Black is stocked; red bronze and silver are to order, so say which you want. The rest of the range is in smart locks. The app is covered at tuya.com.