How to Encrypt Files & Folders: Complete Guide for 2026 by Christopher Owolabi

Updated on: December 29, 2025
Former Writer

Encryption protects data by making it unreadable. The only way to unlock it is with a decryption key. This means that even if someone gains access to your encrypted data, they can’t see it without providing some kind of authorization. It’s a simple but powerful way to keep sensitive information private, whether it’s stored on your device or shared online.

There are lots of easy ways to encrypt sensitive files. Every major operating system provides users with some method of manually encrypting their files and folders. Additionally, encryption is built into many tools, like messaging services and cloud storage providers. Password managers, like 1Password, can store your sensitive information in an encrypted vault.

Keep reading to learn how you can encrypt files on your own. I’ll also go over best practices for efficient file and folder encryption and how it’s built into third-party tools.

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 How Does File Encryption Work?

File encryption works by scrambling content (text, image, video, etc.) in an original file into unreadable characters. This ‘scrambling’ works using complex, uncrackable, and randomized algorithms. In tandem with this process, a decryption key is created, providing the only realistic means of making the data readable in its original form. Keys are usually protected by passwords, key files, strings of bits, or biometric information.

When attempting to open an encrypted file, you’ll usually be prompted to enter a password. With older encryption methods, a password could be the decryption key. With most modern methods, entering a password is just a required step to access the actual encryption key. The authentication process, deployment of the key, and decryption process generally all take place in the background once you provide the correct credentials.

The most widely used encryption methods today have never been cracked. These include:

• OpenPGP.
• 256-bit AES.
• SHA-3.

You don’t need to worry about these technical standards, as long as you choose a reliable file encryption service. The vast majority of top password managers use 256-bit AES encryption, as do the default file-encryption tools included with major operating systems.

How to Encrypt Files on Any Device (Simple but Effective)

There are multiple methods you can use to encrypt your files. The process of encrypting a file depends on your operating system. Below, you’ll discover how to:

• Encrypt files on a Windows PC.
• Encrypt files on Mac.
• Encrypt files on mobile (Android & iOS).
• Encrypt Word documents.

How to Encrypt Files on a Windows PC

The fastest and quickest way to encrypt files and folders on a Windows PC is by using the built-in Windows encryption tool. Once encrypted, other users on the same device will be unable to access the file or folder. That said, the default tool doesn’t lock the decryption key behind a password. This means that anyone who knows your user password will be able to view the encrypted files. If this is a problem, download a free, easy-to-use third-party tool like VeraCrypt.

That said, the default option does protect you from some methods that bypass Windows user passwords. If your device is stolen, the thief can’t simply plug your hard drive into another device and access the encrypted file.

However, it’s not an option for securely sharing files over the internet. If you share a file encrypted with this method over, say, email or a cloud storage provider, that version will not be encrypted.

All that said, here’s how to encrypt files or folders using the default Windows tool:

1. Right-click the file or folder you want to encrypt.

2. Click Properties.
3. Click Advanced under the General tab.
4. Select Encrypt contents to secure data. Then click OK.

5. Click OK again in the General tab.
6. You’ll get an option to encrypt just the file or the entire folder. Choose whichever suits you best.
7. Once encrypted, you’ll get a prompt to back up your file encryption key and certificate. Do this to ensure you never lose access to the file.

How to Encrypt Files on Mac

macOS has flexible built-in encryption options to secure individual files or your entire disk drive. I’ll show you how to do both.

How to Encrypt All Files on Your macOS Disk

Encrypting the files on your macOS hard drive, via the built-in FileVault, does more than just protect your Mac behind a password. If your Mac’s disk drive is put into another computer, it’ll require a decryption key to access the data on it.

Here’s how to encrypt all of your Mac’s data this way:

1. Go to your Mac’s settings.
2. Click Privacy & Security, then enable FileVault.

3. When prompted, enter your Mac password.
4. If you don’t have an iCloud account, you’ll be prompted to create one at this stage. Otherwise, simply log in to your existing iCloud account if it’s not already logged in.
5. Choose whether you want to use your iCloud or unique recovery keys to decrypt your hard drive. I prefer iCloud, but this may backfire if your iCloud gets compromised.

6. Confirm your choice, and your disk encryption begins.

Your Mac may run a bit slow during the encryption process. The timeframe also depends on the number, size, and complexity of files on your computer. Once done, though, your Mac starts running normally again.

How to Encrypt Individual Files on macOS

Unlike FileVault, this method allows you to encrypt folders on Macs. There’s no way to encrypt individual files, but you can always create folders that contain a single file. In any case, this method will keep the file encrypted if you share it via cloud storage (for example). However, the files encrypted this way aren’t compatible with any other operating system — not even your iPhone will be able to open the file.

Here’s how to encrypt folders with macOS’s built-in tool:

1. Open Disk Utility on your Mac. You can pull this up by holding CMD + Spacebar to do a quick search.
2. Go to File > New Image > Image from Folder.

3. Select the folder that contains the file(s) you want to encrypt.
4. Click Choose.

5. On the next screen, select where you want the encrypted folder to be saved.
6. You’ll also choose the kind of encryption level. I recommend 256-bit AES encryption for the highest possible security.

7. Set a secure encryption password. I recommend generating and storing a secure password with a reliable password manager, like 1Password.
8. Once the process is complete, the encrypted version of your chosen folder will be saved as a disk image file and can only be opened with the set password.

How to Encrypt Files on Mobile (Android and iOS)

Most smartphones rely on PINs or biometric authentication to keep your data safe from snoopers. This might be enough in most circumstances, but it’s insufficient protection for truly sensitive data. To give files on your phone the top level of protection, you’ll need to download an encryption app. Popular options include AxCrypt, OpenKeychain, and Cryptomator.

The exact process for encrypting mobile files depends on your app and phone, but the steps are generally quite similar. Because it’s free and easy to use, I’ll use OpenKeychain for this demonstration:

1. Your app will probably prompt you to create a key when you open it for the first time. Simply follow the prompts to create your key.

2. Next, select a file to encrypt. With OpenKeychain, you have to first tap the 3 horizontal lines in the top right corner of your screen, and then select Encrypt/Decrypt. Next, tap Encrypt files, and then choose the file (or files) using your phone’s standard interface.

3. Next, click the 3 dots in the top right of your screen. This will open up a new menu where you can set a password. You might also want to check the box marked Delete files after encryption. In any case, set the password you’ll use to decrypt the file.

4. Once you’ve set a password, simply tap the symbol of the floppy disc and padlock to start the encryption process. As soon as you tap, your phone’s file management interface will pop up again. This is how you choose the name of the encrypted file and where on your phone (or cloud storage provider) it will be saved.

You’re done! When you’re ready to decrypt the file, the steps are virtually the same — just tap decrypt instead of encrypt. Keep in mind that not every app will automatically delete the unencrypted file, so you may want to do that manually.

The best encryption tools come from reputable vendors and use top-shelf encryption standards. You should also look for vendors that allow cross-platform compatibility — this will help you seamlessly access the files you’ve encrypted on other devices.

How to Encrypt a Word Document

You can encrypt a Word document — or any other Microsoft Office file — before sharing, uploading it to the cloud, or storing it securely on your device. The process is slightly different on Windows and Mac, so I’ll show you how to do it on both types of computer.

How to Encrypt a Word Document on Windows

1. Open the Word document you want to encrypt.
2. Click File in the upper left corner.

3. Click Info > Protect Document.

4. Choose Encrypt with Password.

5. Enter a password to protect the document, then reconfirm the password.

That’s it! Your document is now protected with encryption.

You should know that there’s no recovery option should you forget the password. Therefore, losing the password means losing access to the document (one more reason to use a top-of-the-line password manager to store your sensitive information).

How to Encrypt a Word Document on Mac

1. Open the Word document you’d like to encrypt.
2. Click Tools in the top ribbon.

3. Click Protect Document….
4. You’ll be prompted to enter a password to open the document and/or edit the document.

5. Re-enter the password when prompted.
6. Click OK.

The next time you go to open the document, you’ll find a lock sign on it. The document remains encrypted even after uploading it to cloud servers or sharing it with anyone.

6 Other Methods to Encrypt Files Securely

Beyond mobile apps and the tools built into software and operating systems, there are other methods you can use to encrypt files and folders securely. In fact, some are more convenient and have better cross-platform compatibility than, for example, macOS’s native encryption tool.

Here are a few to consider:

• Using third-party apps. Some third-party apps like AxCrypt work across mobile and desktop operating systems. This makes it possible to encrypt a file on your Mac, for example, and open the same file on an Android phone.
• Use bundled security solutions. Security solutions like Panda provide a file encryption tool alongside a full antivirus suite. It even deletes the original file after encryption, tying up loose ends. Plus, some plans come with a password manager you can use to store decryption passwords.

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• Use cloud encryption. Cloud encryption tools like Cryptomator allow you to securely encrypt and store your files in the cloud. This beats cloud providers like Google Drive, which hold the decryption key to your files. The best part is that your files are also accessible on any device, regardless of what OS you used to encrypt them.
• Get password managers with cloud storage. Some password managers, like 1Password and Dashlane, offer encrypted cloud storage. Your files are secured behind military-grade 256-bit AES encryption. Just keep in mind that files stored in this way will only be encrypted within the password manager’s ecosystem. Any file you download from your vault will not be encrypted

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• Consider file-specific encryption. As I demonstrated above, some programs, like Microsoft Office, have built-in encryption tools. Check whether whatever program you’re using has something similar.
• Use external drive encryption. You can also encrypt information on external drives to keep the data on them secure against loss and theft. Here’s a quick and straightforward guide to flash drive encryption to get you started.

Best Practices to Follow After Encrypting Files

Encrypting files, folders, and documents improves data integrity and protects the content of the encrypted material. However, you should follow the extra best practices below to ensure the efficacy of your encryption:

• Backup security certificates and recovery codes. Security certificates are often generated on the device you’ve used for encryption. It’s best to back these up securely. Otherwise, you may be unable to open the files on another device or lose access to the file completely. I recommend using a reliable password manager like 1Password to store your recovery codes in an encrypted environment.

• Save encryption passwords. Encrypting Word documents and many other files often requires a password. You shouldn’t use an easy-to-guess password, as that may defeat the purpose of the encryption. Instead, use your password manager of choice to generate and store secure, hard-to-crack passwords. This ensures an extra layer of security between your encrypted files and a hacker.
• Delete original files. Some encryption methods create a copy of the file to be encrypted, leaving the original untouched. When this happens, anyone with access to your device can still access the original, unencrypted file. Remember to delete the originals to prevent unauthorized access.

How to Decrypt and Use Encrypted Files?

The right way to decrypt and use encrypted files will depend on how they were encrypted. Therefore, you might have to use a password, encryption certificate, recovery code, or a combination of these to regain access to an encrypted file.

Furthermore, the encryption method determines whether the files can be decrypted on another device or another operating system. For example, you can decrypt Word documents on any desktop computer or smartphone. However, you can’t decrypt disk images created on macOS on Windows, Android, or even iOS devices.

Frequently Asked Questions