Update 1 (08/05/2020 @ 07:55 AM ET): Safe Folder within Files by Google is now officially rolling out. Scroll to the bottom for more information. The article as published on August 4, 2020, is preserved below.

Files by Google is a file manager app for Android that started out as a simple file cleaner and browser for Android Go Edition devices, but it has grown so popular over the years that Google essentially made it the de facto file manager app in Google Mobile Services. The app has received a handful of new features over the years, and the latest one that's now rolling out to users is a Safe Folder to hide your private files.

Back in June, we spotted a new "Safe Folder" feature in development in the Files by Google app. The Safe Folder appears as a button in the "Collections" section of the "Browse" tab. Files added to the Safe Folder can only be accessed after entering a 4-digit PIN but can be freely moved in or out of the folder. Google encrypts the files in the Safe Folder, meaning they can't be decrypted if you ever forget the 4-digit PIN. Furthermore, the Safe Folder isn't saved to the cloud, so you can't transfer its contents between devices.

The Safe Folder feature is currently rolling out for users with Files by Google version 1.0.323, according to AndroidPolice. You can download this version from APKMirror or from the Google Play Store link embedded below.

Our tipster informed us that the feature is available for them on the Android 11 Beta, but there's no indication the feature requires a specific Android version. One issue you may come across when seeing the feature for the first time is a notice that the feature isn't supported anymore—yes, even though it just started rolling out, Google has already prepared for its eventual deprecation. We have no idea what Google plans to do with this feature, so at the moment, I would advise against using the Safe Folder to store any critical documents.

Thanks for the tip, @Alpertcr7!

Update: Official announcement by Google for Safe Folder within Files by Google

Google has made an official announcement that Safe Folder within Files by Google is now rolling out.

Safe Folder is a secure, 4-digit PIN-encrypted folder that protects your important documents, images, videos, and audio files from being opened or accessed by others. The folder is securely locked as soon as you switch away from the Files app, so none of its contents can be accessed when the app is in the background. As a security assurance, it will ask for your PIN again on reentry.  Even people that don't share devices can benefit from keeping the most important files safe.

The Safe Folder feature has begun rollout in beta. Availability will gradually expand over the following weeks.