'Knock' iOS App Uses Bluetooth 4.0 to Replace Password Unlocking on Macs - MacRumors
Skip to Content

'Knock' iOS App Uses Bluetooth 4.0 to Replace Password Unlocking on Macs

by

Knock, a newly released app for both iOS and Mac, is designed to allow users to unlock their Macs via Bluetooth with an iPhone, replacing traditional password logins.

After downloading the Knock app for iOS and the accompanying app for the Mac, an iPhone can unlock a connected Mac with two knocks on the back of the iPhone. The iOS app pairs specifically with the Mac app, which creates a secure connection between the two, and the process does not require opening the Knock app.

Faster and safer than typing a password, for iOS and Mac.

You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app— just knock on your phone twice, even when it's in your pocket, and you're in.

Using Knock won't drain your iPhone's battery, even if you use it all day every day. Knock securely communicates with your Mac using Bluetooth Low Energy, a new technology that draws very little power.

Because it uses Low Energy Bluetooth 4.0, Knock is compatible with the iPhone 4s or newer, along with the 2011 MacBook Air or newer, the 2012 MacBook Pro or newer, the 2012 iMac or newer, the 2011 Mac mini or newer and the 2013 Mac Pro.

Knock for iOS can be downloaded from the App Store for $3.99 [Direct Link]. The accompanying Mac app can be downloaded from the Knock website for free.

Top Rated Comments

Reason077 Avatar
162 months ago
And if your iPhone breaks somehow, how do you access your mac then?
Due to the advanced security, it's impossible. You need to buy a new Mac.
Score: 33 Votes (Like | Disagree)
162 months ago
Broken iPhone incoming.

Hey don't Knock it till you try it
Score: 28 Votes (Like | Disagree)
3bs Avatar
162 months ago
And if your iPhone breaks somehow, how do you access your mac then?

Just type in the password?
Score: 15 Votes (Like | Disagree)
Reason077 Avatar
162 months ago
The guy in the video looks like a giant douche with his silly beard. I'd like to "knock" him. In the face.
Score: 15 Votes (Like | Disagree)
162 months ago
My iPhone has a cracked screen. I knocked. Cut my hand. Bleeding

Just called my lawyer..
Score: 14 Votes (Like | Disagree)
3bs Avatar
162 months ago
'Knock' iOS App Uses Bluetooth 4.0 to Replace Password Unlocking on Macs

Just make sure you remember to knock the back of your iPhone!

Unless you have a naked iPhone 4S, that is. Given how easily I've seen the backs of iPhone 4/4S break, knocking it anywhere is probably best avoided.
I think you're exaggerating. They said knock, not punch :p

Sure drops might break it but simply knocking can't possibly break the back unless there was already serious structural damage.
Score: 9 Votes (Like | Disagree)

Popular Stories

iOS 26

iOS 26.4 Adds Two New Features to CarPlay

Tuesday March 24, 2026 1:55 pm PDT by
iOS 26.4 was released today, and it includes a couple of new features for CarPlay: an Ambient Music widget and support for voice-based chatbot apps. To update your iPhone 11 or newer to iOS 26.4, open the Settings app and tap on General → Software Update. CarPlay will automatically offer the new features so long as the iPhone connected to your vehicle is running iOS 26.4 or later....
Apple Business hero

Apple Unveils 'Apple Business' All-in-One Platform

Tuesday March 24, 2026 8:53 am PDT by
Apple today announced Apple Business, a new all-in-one platform that unifies device management, productivity tools, and customer outreach features. The service is designed to be a consolidated replacement for several of Apple's existing business-focused offerings, including Apple Business Essentials, Apple Business Manager, and Apple Business Connect. It provides organizations with a single...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 3, AirPods Pro 2 and AirPods 4

Tuesday March 24, 2026 12:31 pm PDT by
Apple today released new firmware for the AirPods Pro 2, AirPods Pro 3, and the AirPods 4. The firmware has a version number of 8B39, up from 8B34 on the AirPods Pro 3, 8B28 on the AirPods Pro 2, and 8B21 on the AirPods 4. There is no word on what's included in the firmware, but Apple has a support document with limited notes. Most updates are limited to bug fixes and performance...