Way back in Android 8, Google introduced a protected folder in the Files application that password-protects access to any files within. That protected folder is called the Safe folder and it's built-in and free to use.

See also

• These are my 5 favorite AI chatbot apps for Android
• How to transfer data from Android to an iPhone quickly and easily
• How to enable the free Google One VPN on your Pixel device
• How to customize your Pixel screensaver (and why you should)

If you're uncertain as to why you might need to use such a file, consider this: You have sensitive documents on your phone. 

Maybe they were sent to you from your place of employment, or maybe it's travel documentation, bank documentation, images of your driver's license, or your COVID-19 vaccine card. 

Whatever it is you want to safeguard from prying eyes, this folder is where you want to save it. 

Also: How to clear the cache on your Android device (and why you should)

Interestingly enough, Google Photos has a similar feature, called Locked Folder, where you can password-protect images so that only those with the passcode can access them. This is the same thing, only in a different app.

Let me show you how to use Safe folder in the Android Files app.

What is the Android Files Safe folder and how do you use it?

Requirements

The only thing you'll need is a device running on at least Android 8 -- which should cover just about everyone -- as a bare minimum of devices are using an older version of Android. That's it. Let's protect some files.
One thing to keep in mind as you follow along is that screenshots have been disabled for certain secure Android components. That means I won't be able to share with you visuals for every step of the process. I will, however, do my best to explain everything such that you don't need images.

1. Open Files

Open your App Drawer by swiping up on your home screen. Locate and tap the icon for Files.

The Files app launcher is accessible from the App Drawer.

2. Open Safe folder

Near the bottom of the Files app, tap "Safe folder."

Accessing the Safe folder from within Files.

3. Choose your lock option

In the resulting window, you are given the option to lock the folder with either a PIN or Pattern. In this screen, tap either PIN or Pattern to make your choice. 

Also: The 7 best Android phones

Once you've selected an option, you'll then be asked to set either the PIN or Pattern for the Safe folder. After you've successfully set the lock, tap Okay when prompted. The Safe folder is ready to be used.

Now that you've set up your Safe folder, how do you use it? It's actually quite simple