How to Encrypt/Password Protect Files on Android

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We have seen how you can hide your photos and videos on Android. We have also discussed how one can lock an app and secure messages using a password. But what about individual files saved on our SD Card? What if someone wants to lock a PDF, a document or any other file that he wants to hide using a password?

Today we will talk about a simple tool for Android called File Locker, using which you can easily lock any file using a password and secure the access to it. So let’s see how the app works.

Locking the Files

Step 1: Download and install File Locker on your device from the Play Store to get started. The app works on all the devices running on Android 2.1 and above.

Step 2: After you install the application, launch it. The app will look like a simple file manager and will display all the files and folders on your Android. To lock a file, browse for it and long tap on it to open a popup menu.

File Locker (2) File Locker (7)

Step 3: In the popup menu, select the option Lock. You can even batch select files and lock them at once. After you select the lock file option the app will ask you for the password you use to encrypt your files, after providing which it will hash the contents of your files.

File Locker (1)

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Note: The app does not provide a master password option and asks for a new password every time you try to lock a file. As a word of advice I would recommend you use the same password all the time to keep things a little simple.

After the file’s been locked, it cannot be read using any app installed on your device or even a computer. Let’s now see how to unlock the files.

Unlocking the Files

Open the Locked tab to see all the files you have locked using the app. To unlock a file, simply tap on the lock icon next to the file and provide the password. Put a check against the option if you want to be locked automatically when you exit the app.

File Locker (6)File Locker (4)

After a file has been unlocked you can view them in the unlocked tab. You can open the file in their respective viewer right from File Locker app itself.

File Locker (5)

Watch Out For the Following

  • There’s no password recovery option in the app as it does not store your password anywhere on the device. The app just does a simple file checksum while unlocking the file. So if by any chance you forget the password you used while locking the file, you will lose that file forever.
  • While locking a file, the app will give the file a hashed filename. Under no circumstances you should rename the file using any other file managers. If you do it, the app will not be able to read the hashed file and will fail to unlock it.


So keep the points in mind while using the app to lock your files. If you know of a similar app for Android, which can help you with locking the files in a better way, don’t forget to share it with us.

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Show archived comments (8)

Archived Comments

  1. John Doss says:

    I’m using aVault to protect my work Office documents. It has the advantage of letting me automatically edit the encrypted files, keeping them always encrypted. See

  2. Graham says:

    Worst app I’ve ever used. Zero rating. I’ve just downloaded and installed it and ran it to lock 951 files containing photos and videos. When I unlocked them the app only recognized and unlocked 622. The other remaining files are there but r locked and this app that locked them doesn’t even recognize them to unlock them. They appear to have been corrupted as they show a 0 file size now. Thankfully I had a backup of all the files on my PC and I can restore them but requires time to do. Forget this app

  3. Dara Yuk says:

    Try File Locker for Android from this site It is easy to use and fast to lock and unlock large files. Its source code and tutorial are free..

  4. Brian says:

    Works until you uninstall the app…then all the files are unlocked! Great security…lol.

  5. TiagoTiago says:

    How about Encdroid? What do you think of it?

  6. idroid says:

    Try NNI File Protector from the Play Store it’s fast to lock and unlock large files and have more functions.

  7. Utkarsh says:

    I need an App Locker which would just lock all my apps & files in their original location(External Memory Card) – My phone memory is too low & I cannot use an app which would transfer the files from External Memory Card to Internal Phone Memory. Please suggest me an app.
    U can also email me suggestions ([email protected])

  8. Hamid says:

    helo ! i used file locker and i locked my files but unfortunately file locker deleted by me and now i can not open my files i also installed file lock again and opened but faile please help me files available but how to i open help me plz