Product Review: Master Lock 4400D Indoor Bluetooth Smart Padlock

Today, we’re going to review the Master Lock 4400D, an indoor Bluetooth Smart padlock. (List price $70.)

 I want to believe...

I want to believe...


The purpose of an indoor padlock isn’t to lock up your bicycle, because the smart feature is electronic and the elements would be problematic for the indoor model. (There is also an outdoor model, which we may review at some future date.) The purpose of an indoor lock is generally a locker at the gym, indoor storage unit, or some other public place which is out in the weather and where you’re responsible for your own security.

The Good

This is a Master Lock and is accessible from an app on your smartphone. That means you can share it (or not) regularly or intermittently with friends without the need for a key, or a forgettable combination. There is a lock history, tamper alerts, and a low battery alert. Backup access is available with a code/keypad. There is nothing to ‘pick’.

If your phone is stolen, there is a bluetooth revocation option on their website. There is a ‘locker mode’ setting, in case you decide to leave your phone inside the locker. 

The rubber cover has a nice feel to it, very grippy. The unit is 3 inches tall, 2 inches wide,  ⅞ in tall, 3/16 wide. 9/32 hasp. U-shaped boron carbide hasp with a anti-shim locking mechanism and military grade bluetooth encryption. 

Most people love this lock. They love the technology and say it works flawlessly well. It can be used in a security situation where many people need access, but that access needs to be monitored and controlled. This lock works well for that, and they don’t worry about the lock getting picked. But...

The Bad

The people who hate this lock absolutely detest it. Over 20% of all reviewers gave it the poorest rating possible. Some because they had trouble locking it. Some because they had trouble unlocking it. Some because the shackle is too thick to fit into the thing they wanted to lock (gate, locker). 
One reviewer pointed out the the whole point of having a Bluetooth app lock is convenience, but if one has to get out their phone, unlock it, launch the app, and then open the lock, then the point of time convenience is totally lost.

FInal Thoughts

The general undertone is that the app that works the lock isn’t very ‘user friendly’, and that Master Lock needs to work out some of the bugs before it becomes a hit. For example, in order to use the app, you need an 8-digit number, and one user said if it came to that, a combination lock is fewer numbers.

This happens quite frequently with technology--a new, expensive product will come out, but it’s pushed on the market so fast, they haven’t really worked out all of the bugs.

The problem, of course, is that with security, bugs are poorly tolerated. The Noke Bluetooth smart padlock had just as many terrible reviews and not as many great reviews. This tells me that while people really are excited about this new technology, when the reality doesn’t live up to their hopes, they’re terribly disappointed. So, buyer beware that you will either love this, or hate it fiercely.  

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