Guides

This hub is the questions that block a purchase - the ones you have to answer before a product shortlist means anything. Will this fit my door. Does it stop working when the wifi drops. Where does the footage go. What does Matter actually change. Each guide answers its question in the first sixty words and then explains the mechanism underneath, because the short answer is what you came for and the long answer is what stops you buying the wrong thing twice.

How these guides are built

Products we claim to have tested: zero. Nearly every page in this category says it spent a month with a dozen locks on its own front door. We have not done that, we are not going to say we did, and stating it plainly is the point rather than an apology. What we do instead is specific and checkable.

We work from published manufacturer specifications and installation manuals - the documents that contain the backset range, the transformer voltage window, the battery chemistry and the magnet gap tolerance, and which almost nobody quotes back to you. We work from published standards: the BHMA and ANSI A156 documents behind a lock's grade, the Matter and Thread specifications, IP ingress ratings, and what each of those actually certifies. And we show the arithmetic: battery life against cycles per day, five-year running cost against purchase price, storage capacity against bitrate. When a number comes from a manufacturer's own claim rather than a standard, we say so in the same sentence.

Where the sourcing rules and the scoring come from is set out in full on how we pick, which is the page to read first if you want to know how much weight to give anything here.

Fit and installation

The most expensive mistake in this whole site is a lock that does not physically fit, and it is entirely avoidable with a tape measure. Will a smart lock fit my door walks through backset, cross-bore, edge-bore, door thickness and the obstructions that catch people out - raised panels, glass inserts, metal slabs, and a deadbolt that already needs persuading. Once you know the answer, how to install a smart lock covers the install itself, including the alignment check that decides whether auto-lock is safe to switch on.

Both of those assume a door that can take a deadbolt. Smart locks for storm doors covers the case where it cannot: a storm door slab is roughly half the thickness a deadbolt needs, so the guide explains the measurement, says plainly that no mainstream smart lock fits, and sets out the three things that do help instead.

Connectivity and protocols

Protocol confusion is the second-biggest source of returns. Do smart locks need wifi separates what genuinely stops working during an outage - remote unlocking, away-from-home notifications, remote guest codes - from what keeps working, which for most locks is everything you do while standing at the door. Matter and Thread, explained deals with the other half: which devices need a border router or a coordinator, what Matter certification actually promises, and where it still falls short of the marketing.

The security half of the same question - what each radio exposes, and to whom - is separated out in smart lock security risks by protocol. It sorts Wi-Fi, Bluetooth, Zigbee, Z-Wave and Thread by where an attacker would have to be standing, which turns a vague worry into a short and mostly reassuring list.

Storage, cost and the safety question

Local storage versus cloud recording is the guide that changes the running cost of a whole system, because it determines whether you are buying hardware once or renting retention forever. It covers what happens to each model during an internet outage, what happens if the camera is removed, and how to get a clip out as a file.

The two remaining guides answer the questions people ask before they will commit at all: whether a keypad or app-controlled lock is a sensible replacement for a mechanical one, and whether a doorbell earns its place as a first device. Both are written the same way as everything else here - the answer up front, the reasoning below it, and a plain statement of the case for not buying.

What most buyers get wrong

Researching the product before the constraint. Two hours comparing four locks is wasted if three of them need a bore your door does not have. Ten minutes with a tape measure comes first, always.

Reading only the guide that matches the thing they already want. The storage guide changes camera choices, the protocol guide changes sensor choices, and both change what a subscription is worth. They are not independent.

Treating a manufacturer figure as a measurement. A two-year battery rating is a claim made under stated conditions, and the conditions are in the manual. When we quote a figure like that, we name whose figure it is, so you can weight it accordingly.