You are standing in the hardware aisle, or scrolling a product page at midnight, and forty locks are staring back at you. There are deadbolts, keypads, smart locks, and something with a fingerprint reader, and they all promise to keep you safe without ever explaining which one belongs on your door.

This guide walks through the common types of locks used in homes, what each one is actually built for, and where it fits. Some protect an entry door, some are meant only for an interior room, and a few have quietly changed what a house key even means. By the end you will know which type suits each door you own.

What really separates one lock from another

Walk down the lock aisle and everything looks like it is competing on security, but that is only part of the story. Almost every lock in a home is balancing three things at once, and the reason there are so many types is that each one leans harder on a different one:

Once you know which of the three matters most for a given door, the right type almost picks itself. A front entry leans on security, a side door the whole family uses leans on convenience, and a home with people always coming and going leans on control. Keep those three in mind as we walk through the types below.

Deadbolts: the workhorse of your exterior doors

When people picture a lock that actually secures a door, they are picturing a deadbolt. It throws a solid metal bolt into the door frame, and unlike a spring latch it does not push back open under pressure. This is the lock that carries your front and back doors.

Almost every deadbolt comes in one of two forms, and the difference is less about raw strength than about how you get out from the inside, which matters more on a main entry door than most people expect:

A common find on a rekey is a back door still turning on the builder’s original lock years after move-in, the kind of thing we check first at Texas Premier Locksmith. If a deadbolt feels loose or does not throw fully into the frame, that is worth fixing before it fails on a cold morning.

Knob and lever locks: made for inside, not the front line

A doorknob lock or a lever handle lock has its place, but that place is usually inside the house. The locking mechanism sits in the knob or lever itself, which means it can be twisted or forced far more easily than a deadbolt. On an exterior door it should never be the only thing standing guard.

Both types still do useful work in the right spot, as long as you are honest about what that spot is and do not ask a knob lock to guard a door that opens straight to the street:

If a knob lock is the only lock on a door that leads outside, treat that as a gap to close, not a finished setup.

Mortise locks: the heavy option in older and higher-end homes

In an older bungalow or a higher-end home, you may find a mortise lock, recognizable by the larger, heavier hardware and the deep pocket cut into the edge of the door. Inside that pocket sits a solid lock body that combines a latch and a deadbolt in one strong unit.

Mortise locks are durable and hold up to heavy daily use, which is why they show up on solid wood doors and homes built to last. They are more involved to install or replace than a standard bored lock, so this is one where a proper fit matters. If you own a home with original mortise hardware, it is often worth restoring rather than swapping it for something lighter.

Smart locks: your phone becomes the key

A smart lock replaces the key with your phone, a code, or a tap, and connects to your home network so you can lock up or let someone in from anywhere. For a family that is forever texting to ask whether the door got locked, that alone is the appeal.

The value of a smart lock is less about the hardware itself and more about the control it hands you over who comes and goes and when, which is what earns it a place on a busy household door:

Batteries and connections do need attention, and the security tradeoffs deserve a closer look, which we compare directly in are smart locks safer than traditional locks. Most models keep a mechanical key backup, so you are never fully locked out when the battery dies.

Keypad and keyless deadbolts: a code instead of a key

A keypad or keyless deadbolt sits one step short of a full smart lock. You unlock it by punching in a code, with no phone and no internet required, and many are simple battery-powered keypads, which keeps them reliable.

These fit the household that is tired of hiding a spare under the mat and tired of cutting a new key every time someone needs access, because a code quietly does all of that work instead:

For a busy side or garage entry door, a keypad deadbolt removes the daily key fumble while still throwing a real bolt into the frame.

Biometric locks: a fingerprint instead of anything to carry

A biometric lock reads a fingerprint instead of accepting a key or a code. For a home with kids who lose keys, or anyone who would rather carry nothing at all, the appeal is obvious, since you become the key yourself.

These locks store a set of approved prints and open the moment a matching finger touches the reader. They usually keep a keypad or key backup too, in case a print does not read on a cold or wet day. How the technology holds up and where it fits best is its own subject, covered in how biometric locks work. As a home door lock, treat biometrics as a convenient front end on top of a solid deadbolt, not a replacement for one.

Padlocks: for gates, sheds, and anything off the house

Not every lock in a home is on a door. A padlock is the portable option for a gate, a shed, a fence latch, or a storage unit. Look for a shrouded or boron shackle if it lives outdoors, since a cheap padlock is quick work for a pair of bolt cutters. Keep padlocks for the outbuildings, and let dedicated door locks handle the house itself.

A quick word on lock grades

One label cuts across every type above. Locks are rated by ANSI and BHMA as Grade 1, Grade 2, or Grade 3, a score for how much force and daily wear they can take before they start to fail, and it is worth knowing which is which:

When two deadbolts look identical on the shelf, the grade is often what separates the one that lasts from the one that loosens within a year. For the doors where you want the most resistance to force, picking, and copying, that is the territory of high-security locks, which sit a step above the usual grades.

How to choose the right lock for each door

The right lock is rarely one answer for the whole house, since it changes door by door and with how you actually live, so it helps to walk through the situations that come up most often:

If your real question is which type stops a break-in and what it costs, that is the security side of the decision, and we lay it out in best locks to prevent home burglaries.

Not sure which lock belongs on which door?