Best Retrofit Smart Locks (2026 Guide)

The Bottom Line: The August Wi-Fi Smart Lock (4th Gen) is the best all-around retrofit smart lock, offering built-in Wi-Fi and a compact profile. If you want a completely invisible install that leaves your exterior hardware untouched, the Level Bolt is unmatched.

Here at Door Security Group in Manhattan, retrofit locks are our most popular request for apartment dwellers. Since landlords usually prohibit changing the exterior hardware, retrofit locks are the perfect solution. We coordinate these installations daily in NYC and across the country through our nationwide partner network.

Why Trust Us?

We've installed retrofit locks on everything from pristine new doors to 100-year-old warped frames in historic brownstones. We know which motors have the torque to turn a stiff deadbolt. Review our deadbolt grades to understand your existing hardware.

Top Retrofit Picks

1. August Wi-Fi Smart Lock — ~$229

The industry standard for retrofits. It replaces only the inside thumbturn.

• Pros: Compact size, built-in Wi-Fi, incredibly easy install, universally compatible with most single-cylinder deadbolts.
• Cons: Battery life can be short; visible on the inside of the door.

2. Level Bolt — ~$199

Unlike August, which replaces the thumbturn, Level Bolt replaces the inside mechanism of your deadbolt, leaving both your exterior keyhole and interior thumbturn completely original.

• Pros: 100% invisible, uses standard CR2 batteries, HomeKit compatible.
• Cons: Requires specific compatible deadbolt brands (Schlage, Kwikset); more involved installation.

3. Wyze Lock — ~$129

A fantastic budget-friendly retrofit.

• Pros: Very affordable, includes gateway hub, auto-unlock features.
• Cons: Utilitarian design, motor is somewhat loud.

Comparison Table

| Model | Retrofit Type | Aesthetics | Est. Price | |---|---|---|---| | August Wi-Fi | Interior Thumbturn | Visible | $229 | | Level Bolt | Internal Mechanism | Invisible | $199 | | Wyze Lock | Thumbturn Cover (Hub Included) | Visible | $129 | | SwitchBot Lock | Thumbturn Cover (Hub Required) | Very Bulky | $119 |

Buying Guide & FAQs

Before buying a retrofit lock, ensure your existing deadbolt operates smoothly. If you have to push or pull your door to lock it, the smart lock motor will jam. You may need our door reinforcement solutions to align the strike plate perfectly. If you rent, August or Wyze are your best bets since you can easily remove them when you move; if you own your home and care about aesthetics, the Level Bolt is unmatched.

Want to know if your current lock is compatible? Contact me with a photo of your door, and our team will guide you to the right smart locks.

Explore Related Security Guides

• Best Smart Door Locks
• Best Smart Locks for Apartments
• August Smart Lock Review
• August Smart Lock Pro Review
• Best Apple HomeKit Smart Locks
• Best Smart Locks That Work with Alexa
• Smart Lock Buying Guide

From Other Categories:

• Best Deadbolt Locks for Home Security
• Best Outdoor Wireless Security Cameras

Not sure where to start? Take our free security assessment for a personalized recommendation — or meet our Manhattan-based team.