This article mainly talks about WhatsApp desktop password protection. It also shows you how to put a lock on WhatsApp mobile app.
WhatsApp is one of the most popular and widely used instant messaging and VoIP services in the world. It allows users to easily send messages, make calls and share files. WhatsApp is available as a mobile app for iOS and Android devices. It also provides a desktop app for Windows and Mac computers. If you want to use WhatsApp in browser, you can navigate to its web site and then link your phone to your computer.
In the digital age, privacy protection is more important than ever. WhatsApp has taken efforts to protect users’ data. For example, it puts end-to-end encryption on chats and backup data.
What can users do to protect privacy on WhatsApp? You can sign out of the app, but it will be impractical because you probably use WhatsApp on a daily and even hourly basis. Also, you can lock your computer or phone when you are away from it, but sometimes there are situations where you have to let others use your device. There’s a solution! You can lock WhatsApp desktop or mobile app. Let’s look at how to set password for whatsapp desktop and mobile app below.
Cisdem AppCrypt
Free Download Windows 11/10/8/7 
Free Download macOS 10.12 or later
Windows doesn’t come with a feature for you to put a password on individual apps. Luckily, there are third-party tools available. You can easily and effectively password protect WhatsApp desktop with Cisdem AppCrypt, the best app locker for Windows.
1. Download and install AppCrypt on your PC.
Free Download Windows 11/10/8/7
2. The first time you open the tool, set a password.
3. Open File Explorer. On the left, choose This PC. Enter “whatsapp” in the search box, and you will see WhatsApp.exe.
4. On the taskbar, click the tool’s icon. If you can’t see it, click the Arrow Up icon first.
5. You will be prompted to enter the password. Enter the password to access the tool’s interface.
6. Drag WhatsApp.exe into the interface. Alternatively, click the Add button to add WhatsApp.exe.
Now the WhatsApp desktop app is locked.
When you or someone else tries to open it, a dialog box will show up asking for password. To unlock WhatsApp, one will need to enter the correct password.
If one enters the wrong password, WhatsApp will still be locked and secured. And AppCrypt will record this failed attempt, with the date and time.
To remove the lock, go to the tool’s interface (which requires the password), select WhatsApp, and press the Delete key.
As long as AppCrypt is running, it will prevent any unauthorized access to the locked WhatsApp. Here is how to make this tool run all the time. Click Preferences 
in the toolbar. Enable Launch at system startup.
There is also an option, which, if enabled, will automatically relock WhatsApp when WhatsApp is unlocked and inactive for a period of time. Enable the option if needed.
You lock WhatsApp for the sake of privacy protection. If you want to lock certain apps during certain hours to reduce distractions or to limit screen time, the Custom Schedule feature can help.
If you are a Mac user who wants to prevent others who can access your Mac from opening your WhatsApp desktop app, you can also use AppCrypt. It’s easy to use with a simple interface. Blow is how to use it to put WhatsApp desktop password lock.
1. Download and install AppCrypt on your Mac.
Free Download macOS 10.12 or later
2. Set a password when you open it for the first time.
3. Click the lock icon in the top menu bar and choose Open Main Window.
4. Enter the password.
And you will see the main window.
5. Under the App Lock tab, click the Add button. In the Applications folder that appears, select WhatsApp and click Open. Alternatively, you can use drag and drop.
It is that easy.
Here are some useful details to know.
There is also a feature to block websites. Choose the Web Block tab in the main window. You can block specific websites/webpages including whatsapp.com on Chrome, Safari, Opera, etc. To unblock WhatsApp website, just click AppCrypt’s icon in the menu bar. Click Disable Web Block and enter the password.
The content above is for WhatsApp desktop app. Now let’s talk about the mobile one.
To offer additional security, WhatsApp allows iPhone users to protect its app with Touch ID or Face ID, depending on the iPhone model.
Note: When WhatsApp is locked, if a call comes in, you can still answer it. And you can still reply to messages from notifications.
To be able to use Touch ID or Face ID for WhatsApp, you need to first set up Touch ID or Face ID in your device’s settings.
1. Open WhatsApp on your iPhone.
2. Tap Settings in the lower right corner of the screen.
3. Go to Privacy > Screen Lock.
4. Enable Require Face ID or Require Touch ID.
5. From the three options allowing you to decide how often the WhatsApp lock will ask for fingerprint or face recognition, select the option that suits your need.
Before October 2019, there were two ways for Android users to secure WhatsApp app. If your phone provides a built-in feature to lock apps, then you can readily use it. If not, you can use a third-party app locker. On October 31, 2019, WhatsApp introduced fingerprint lock for Android. Note that it’s only for Android devices with a fingerprint sensor running Android 6.0+. And it doesn’t work on certain Samsung models (Samsung Galaxy S5, Samsung Galaxy Note 4, or Samsung Galaxy Note 8).
Also note that the locking doesn’t prevents you from answering a WhatsApp call.
If you turn on the option Show content in notifications, you will be able to preview messages inside message notifications.
To turn off the fingerprint lock for WhatsApp, go to the app’s settings and turn off Unlock with fingerprint.
Above are how to password lock WhatsApp app on desktop and mobile. How about WhatsApp web? Although its web version is limited in some features, some users still used to using it on the web for saving memory or other reasons. Fortunately, there’s a Chrome extension can help you use WhatsApp web safely.
Password Lock for WhatsApp Web allows you to password protect your WhatsApp web account on Chrome browser. Once adding this extension, it’ll prompt you to set a password the next time you visit WhatsApp web. Then the password will be required every time you or other users of this computer try to access WhatsApp web. What’s more, to further protect your privacy, this extension enables you to password lock WhatsApp web instantly. Just click the Chrome extension icon on the top right corner. Tap on this WhatsApp locker extension to activate it quickly.
As you can see, it’s easy to apply WhatsApp desktop password protection and mobile app fingerprint locks. By doing so, you can keep your chat, conversations and privacy away from prying eyes. If there isn’t a built-in feature to lock apps, you can turn to third-party solutions such as AppCrypt for Mac. In addition to adding WhatsApp lock, you can also use the same tool to lock other apps on your computer.
Rosa has worked in Mac software industry for more than eight years. She believes that the purpose of software is to make life better and work more productively. In addition to writing, Rosa is also an avid runner.
Lee
I had no idea you could lock WhatsApp on desktop and mobile! This is a game changer for me since I'm always worried about someone snooping through my messages. Thanks for the great guide, it was really easy to follow and now I feel much more secure. Cheers!
Rubenbowen
It's nice to be able to securely lock your WhatsApp. Especially when friends,family and who know uses my Mac...