10 Different Types of Door Locks and How They Work

There are 10 types of door locks and how they work comes down to one thing: the mechanism inside. Pin tumblers, spring latches, electronic sensors, multi-bolt systems — each one is built for a different purpose. Choosing the wrong type for a given door is one of the most common (and costly) home security mistakes you can make. Explore the full range on our door locks category page before you buy.

Most homeowners have several different lock types installed without realizing it. According to Wikipedia's overview of security locks, the pin tumbler design — invented in the 1800s — still powers the majority of residential locks sold today. But modern options go far beyond a key-and-cylinder setup, and what works perfectly on your front door is the wrong choice for your patio or filing cabinet.

This guide breaks down all 10 lock types in plain terms, compares their strengths and weaknesses, and tells you exactly which one belongs where.

The 10 Types of Door Locks and How They Work

Each lock type below is built around a core mechanism. Understanding that mechanism tells you exactly how secure it is — and where its limits are.

1. Deadbolts

The deadbolt is the gold standard for exterior door security. Unlike a spring latch (which snaps back automatically and can be slipped with a credit card), a deadbolt throws a solid steel bolt deep into the door frame that won't retract without a key or thumbturn.

A deadbolt is non-negotiable on every exterior door — without one, a door can be opened in seconds with a credit card or a hard shove.

Three main deadbolt types:

• Single-cylinder — key outside, thumbturn inside (the most common residential choice)
• Double-cylinder — key required on both sides (good for doors with glass panels nearby)
• Lockable thumbturn — behaves like a single-cylinder but the thumbturn can be locked from inside

If you want to understand where deadbolts are vulnerable, read our guide on how to pick a deadbolt lock — knowing the weak points helps you choose better hardware and installation methods.

2. Knob Locks

Knob locks are the most common lock on interior doors. The entire locking mechanism lives inside the knob — which is exactly the problem. A hard strike to the knob can snap it off, bypassing the lock completely.

• Best for: interior bedroom and bathroom doors
• Not suitable for: any exterior door used as a primary lock
• How they work: rotating the knob compresses a spring-loaded latch into the door frame

If you have a knob lock on your front door without a deadbolt above it, that is your most urgent security fix.

3. Lever Handle Locks

Lever handle locks use the same spring-latch mechanism as knob locks, but the lever shape makes them far easier to operate — especially for people with limited grip strength. They're the standard in commercial buildings, offices, and ADA-compliant spaces for that reason.

• Common in offices, hotels, schools, and accessible housing
• Easier to torque and force open than a deadbolt — don't use alone on exterior doors
• Available in passage (no lock), privacy (push-button inside), and keyed configurations

4. Padlocks

Padlocks are the only freestanding locks on this list — they don't attach permanently to a door or frame. They secure through a shackle (the U-shaped metal bar) that clips through a hasp, chain, or loop.

Two main types:

• Keyed padlocks — pin tumbler or disc detainer mechanism, opened with a key
• Combination padlocks — no key needed, opened by aligning a numeric or directional code

Look for hardened steel shackles and anti-drill plates when securing a storage unit or outdoor gate — cheap padlocks can be cut in under 10 seconds. Our guide to the best padlocks for storage units covers the top options by security level. And if you've ever lost the key, our breakdown of how to open a padlock without a key walks through your options step by step.

5. Mortise Locks

Mortise locks are recessed directly into the door edge rather than bolted onto the surface. The lock body fits into a pocket (the "mortise") cut into the door, which makes them significantly harder to kick in or pry out.

• Common in older homes, hotels, and high-end residential installations
• Combines a deadbolt and spring latch in a single unit
• More complex to install — usually requires a professional or an experienced DIYer
• Among the most durable and secure options for an exterior door

6. Smart and Digital Locks

Smart locks replace your traditional key with a smartphone app, fingerprint reader, or voice command. Most still include a physical key cylinder as a backup. Smart locks connect via Bluetooth, Z-Wave, Zigbee, or Wi-Fi and integrate with home automation platforms.

Smart locks are only as secure as their firmware and app — always buy from brands that release regular security updates and support two-factor authentication for remote access.

If you're building a connected home, check out our roundup of the best Bluetooth door locks, our guide to smart locks that work with Google Home, or our picks for the best HomeKit smart lock if you're in the Apple ecosystem.

7. Keypad and Electronic Locks

Keypad locks use a PIN code instead of a physical key. They're a popular choice for rental properties, Airbnbs, and family homes where you want to hand out access codes without cutting extra keys.

• Can store multiple PIN codes for different users
• Eliminates lockouts caused by lost keys
• Battery-powered — always keep a spare set nearby and set a reminder to change them every 6 months
• Most models include a physical key cylinder as a backup override

8. Multi-Point Locks

Multi-point locks secure the door at three or more points along the frame — typically the top, middle, and bottom — all activated by a single key turn. They're standard on European composite doors and patio doors.

Multi-point locks spread force across the entire door frame — a kick-in attack that would destroy a single-bolt lock barely shakes a properly installed multi-point system.

• Activated by lifting the handle before turning the key
• Ideal for uPVC, composite, sliding patio, and French doors
• Significantly harder to force open than a standard deadbolt on a patio door

9. Cam Locks and Furniture Locks

Cam locks use a small rotating metal tab (called a "cam") to secure cabinets, drawers, mailboxes, and office furniture. They are not designed for exterior doors — security is minimal and they're easy to pick or drill.

• Common in filing cabinets, office desks, display cases, and mailboxes
• Simple quarter-turn operation — insert key, rotate 90°, cam rotates to block or release
• Suitable for low-security storage only — not for documents or valuables without additional protection

10. Portable Door Locks

Portable door locks are temporary security devices you carry with you for travel. They wedge against the floor or clamp to the door hardware to block the door from opening from outside — even if someone has a valid key to your room.

• Designed for hotel rooms, Airbnbs, and dormitory rooms
• Work independently of the existing door hardware
• Not a permanent replacement — supplement only
• Learn how one of the most popular designs works in our guide on how the Addalock portable door lock works

How the Most Common Locks Stack Up: Pros and Cons

Not every lock type is right for every situation. Here's a side-by-side comparison of the key trade-offs across all 10 types.

A few things stand out in that table. Security level varies wildly within the padlock category — a $10 combination lock and a $90 hardened-steel keyed padlock are not the same product. Always look at the construction, not just the price. And notice that smart and keypad locks rate just as high as deadbolts — the mechanism is solid, but the software layer adds a new attack surface that purely mechanical locks don't have.

What to Expect to Pay for Each Lock Type

Lock prices span a wider range than most people expect. Here's what each tier actually gets you.

Budget Range: $10–$50

• Basic knob locks and lever passage sets for interior doors
• Entry-level combination padlocks (adequate for gym lockers, not storage units)
• Portable travel locks — most solid options sit in the $15–$30 range
• Grade 3 deadbolts — meets minimum standards only, skip these for front doors

Mid-Range: $50–$150

• This is the sweet spot for most homeowners. You get legitimate security without overpaying.
• Grade 2 deadbolts with solid brass construction
• Entry-level smart locks with Bluetooth and PIN access
• Quality keyed padlocks with hardened steel shackles and anti-drill protection
• Electronic keypad deadbolts with multiple user codes

Premium Range: $150–$500+

• Grade 1 deadbolts — commercial-grade, tested for 250,000+ cycles
• Full-featured smart locks with fingerprint, app, and keypad access plus auto-lock
• Multi-point locking systems for patio and French doors
• Mortise lock sets for high-end residential installations

One thing the price table won't tell you: the strike plate and installation matter as much as the lock itself. A $200 deadbolt secured with ¾-inch screws into a hollow door frame is less secure than a $50 deadbolt installed with 3-inch screws anchored into the wall stud. Budget for proper hardware, not just the lock body.

How to Choose the Right Lock for Every Door

Security needs change depending on which door you're locking. Here's how to match the lock type to the location.

Front and Back Exterior Doors

• Install a Grade 1 or Grade 2 deadbolt on every exterior door — this is the baseline, not optional
• Use 3-inch screws in the strike plate to anchor into the wall stud, not just the trim
• Add a knob or lever set below the deadbolt for the latch functionality — but the deadbolt is your actual security
• Consider a keypad or smart lock if you have guests, short-term rentals, or kids who lose keys

Interior Bedroom and Bathroom Doors

• A privacy knob or lever lock is sufficient — these lock from the inside with a push button and release with an emergency pin from outside
• No keyed lock needed unless you're securing a home office with sensitive files or equipment

Patio, Sliding, and French Doors

• These are primary entry points for break-ins — treat them seriously
• A multi-point lock is the best dedicated solution for composite and uPVC patio doors
• For sliding glass doors, add a steel track bar or a keyed sliding door lock in addition to the factory hardware
• A floor bolt at the top or bottom adds a third locking point for minimal cost

Garage Side Doors and Basement Doors

• Treat these exactly like your front door — both are common secondary entry points
• Install a deadbolt in addition to the existing knob lock
• A keypad lock on the garage entry door eliminates the need to carry a house key when you're just running to the car

Lock Mistakes That Compromise Your Home Security

These are the errors that show up over and over. All of them are easy to fix once you know they're a problem.

Using a Knob Lock as Your Only Exterior Lock

Knob locks can be snapped off the door with a single hard strike or bypassed with a credit card in seconds. They are convenience hardware, not security hardware. Every exterior door needs a deadbolt — full stop.

Installing Short Screws in the Strike Plate

Most locks ship with ¾-inch screws that only reach the thin door trim, not the stud behind it. One solid kick at the frame and the trim splits, taking the strike plate with it. Replace every strike plate screw with 3-inch screws immediately. This single fix makes more difference than upgrading to a more expensive lock.

Ignoring Battery Life on Electronic Locks

Keypad and smart locks run on AA or AAA batteries. When they die, you're locked out — or worse, the lock fails open. Set a recurring calendar reminder to swap batteries every 6 months. Most modern models also send low-battery alerts to your phone.

Buying a Lock Without Checking the ANSI/BHMA Grade

The ANSI/BHMA grading system (American National Standards Institute / Builders Hardware Manufacturers Association) rates locks Grade 1 through 3. Grade 1 is commercial-strength. Grade 3 is the minimum legal standard. If the packaging doesn't list a grade, assume Grade 3 or lower. Front doors deserve Grade 1 or Grade 2.

Securing a Weak Door with a Strong Lock

A Grade 1 deadbolt installed in a hollow-core interior door provides almost no protection. The lock is stronger than the door — so the door fails first. Exterior doors need solid-core wood or steel construction. A strong lock on a weak door is security theater.

Fast Security Wins You Can Do This Weekend

You don't need to replace every lock to meaningfully improve your home security. These five changes deliver outsized results with minimal effort and cost.

1. Replace your strike plate screws. Swap out the ¾-inch screws for 3-inch versions that reach the stud. Cost: under $5. Time: 10 minutes. This single change makes your door kick-resistant at virtually no cost.
2. Add a deadbolt to any exterior door that only has a knob lock. A Grade 2 single-cylinder deadbolt runs $30–$60 and takes about 30 minutes to install. Our guide to installing a Kwikset front door handle set walks through the process.
3. Install a door reinforcement kit. These steel wrap-around frames bolt around the door edge and dramatically increase kick resistance. Around $40–$60 and no special tools required.
4. Switch your front door to a keypad or smart lock. Eliminates lost-key lockouts and lets you hand out temporary access codes to guests, cleaners, or contractors without copying keys.
5. Add a portable travel lock to your bag. It weighs almost nothing and gives you real security in hotel rooms and Airbnbs where you can't control the hardware on the door.

These five upgrades take one afternoon and cost under $200 combined. Your home will be measurably harder to breach by the time you're done.

When to Upgrade Your Locks — and When to Skip It

Not every lock needs replacing. Here's how to tell the difference between a security gap and unnecessary spending.

Signs It's Time to Upgrade

• Your exterior door has only a knob lock — no deadbolt
• You've moved into a new home and don't know who has copies of the existing keys
• A lock is visibly worn, stiff, or doesn't engage cleanly
• You're managing a rental property and want keyless access control
• Your patio or French door has only its factory hardware
• You lost a key and can't account for all copies

When Your Current Locks Are Fine

• You already have a Grade 1 or Grade 2 deadbolt on every exterior door with proper strike plate installation
• Your interior door locks are functioning and you're not storing high-value items behind them
• You're considering an upgrade only because the finish is dated — aesthetics don't affect security
• A lock is less than 3–5 years old and shows no signs of wear or damage

The rule is simple: upgrade when there's an actual security gap, not when a shiny new product catches your eye. Focus your budget on the doors that matter most — the ones an intruder would actually try.

Frequently Asked Questions

The lock on your door is only as strong as the frame it's bolted into, the screws holding it in place, and your commitment to actually using it every time you leave — the best hardware in the world means nothing if the basics are wrong.