Encrypt and decrypt files in your browser
This page runs AES-style encryption with the Web Crypto API inside your browser. Files and keys stay on your device. Nothing is uploaded to finish the job.
AES-256-GCM encryption and decryption runs entirely in your browser using the Web Crypto API. Your files and keys never leave your device.
Encrypt/Decrypt Tool
Encrypt or decrypt text and files using various encryption algorithms. All processing happens in your browser - your data never leaves your device.
Input
Click to select a file or drag and drop here
Configuration
Output
Supported Algorithms
AES: Advanced Encryption Standard - Recommended for most use cases. Supports 128, 192, and 256-bit keys.
TripleDES: Triple Data Encryption Standard - More secure than DES but slower than AES.
Blowfish: Block cipher with variable key length (32-448 bits). Fast and secure.
Twofish: Block cipher, finalist in AES competition. Very secure with 128-bit blocks.
Serpent: Block cipher, AES finalist. Considered very secure.
Rabbit: Stream cipher, fast and efficient for large data.
RC4: Stream cipher - Legacy, not recommended for security-sensitive applications.
DES: Data Encryption Standard - Legacy algorithm, not recommended for new applications.
Note: Some algorithms (Blowfish, Twofish, Serpent) may require additional CryptoJS modules. If unavailable, use AES or TripleDES.
AES, TripleDES, Blowfish, Twofish, Serpent, Rabbit, RC4, and more. Choose the right cipher for your use case.
All encryption uses the Web Crypto API in your browser. No data is ever sent to any server.
Encrypt plain text or entire files. Output in Base64 or Hexadecimal. Download encrypted files directly.
Understanding Client-Side Encryption
The Encrypt/Decrypt tool runs entirely in your browser. When you encrypt text or a file, your browser generates a random encryption key, applies AES-256-GCM encryption, and outputs the ciphertext. The key never leaves your device unless you explicitly share it. This means even if someone intercepts the encrypted output, they cannot decrypt it without the key.
This tool is useful for encrypting sensitive data before storing it in cloud drives, emailing confidential documents, or creating encrypted backups. You can encrypt text directly or upload files of any size supported by your browser's memory.
Local Web Crypto, not an upload vault
Encryption here uses the browser’s Web Crypto API on the machine in front of you. The file you select is processed locally. There is no upload step that sends the plaintext to a Vidzilla server for this tool.
That design matters when the file holds private notes, identity scans, or work drafts. You keep custody of the bytes throughout encrypt and decrypt.
If your browser is outdated or Web Crypto is blocked by policy, the page cannot complete the operation. Use a current browser on a device you control.
- Choose the file on your device.
- Pick encrypt or decrypt and the algorithm option shown on the page.
- Save the output locally and store the key where you will find it later.
AES is the recommended choice
When the page offers algorithm choices, AES is the recommended path for new files. It is widely supported in modern browsers through Web Crypto and fits typical file-protection needs on this tool.
Do not invent custom schemes outside the options the page lists. Stick to the recommended AES setting unless you are matching an older file you already encrypted with a different listed option.
Decrypt only works with the same algorithm and key material you used to encrypt. Mismatched choices produce failures or unreadable output.
Encrypt mode and decrypt mode
Encrypt mode takes a readable file and writes a protected output. Decrypt mode takes that protected output and restores the original when the key is correct.
Label outputs clearly. Include encrypt or decrypt in the filename so you do not overwrite the only plaintext copy by accident.
Keep the original until you have opened the decrypted result and confirmed it matches. Then archive or delete according to your own retention rules.
Keys you can actually store
A strong key that you cannot recover is a locked file forever. Write the key into a password manager or another offline store you already trust before you delete plaintext.
Do not paste keys into public chats. Do not save them only in the same folder as the encrypted file if that folder travels together on a USB stick.
If you share an encrypted file with someone else, send the key on a different channel than the file when your threat model requires that split.
Text snippets and whole files
Use the file controls when you need to protect a document, archive, or media file. Use text mode when the page offers it for short notes that never become a separate disk file.
Large files depend on available memory in the browser tab. If the tab crashes on a huge input, split the work with a file-split tool first, or encrypt on a machine with more RAM.
This page does not replace full-disk encryption built into your operating system. It protects individual files you choose to lock before sharing or archiving.
Free local use and what this page is not
Local encrypt and decrypt on this page do not require a Vidzilla account. Processing stays in the browser. There is no cloud vault listing your past files.
This is not email delivery, not a password reset service, and not a recovery hotline for lost keys. Lost keys mean lost plaintext for files encrypted here.
For PDF-only password gates, a PDF password tool may fit better. For packing many files before encryption, build a zip first, then encrypt the archive.
After you finish an encrypt or decrypt pass
Open decrypted outputs immediately to confirm success. Store encrypted outputs with the key reference you saved earlier.
Clear browser downloads clutter so encrypted and plaintext twins do not sit side by side unlabeled.
If something fails, change one variable at a time: file, mode, algorithm, or key. Note what changed so the next attempt is a measured test.
When you encrypt before travel, copy the encrypted file to the travel drive and leave plaintext off that drive. Confirm decrypt works once on a trusted machine before you need the file on the road.
Team handoffs need a written note of algorithm and key location. A file named final-encrypted.bin without that note becomes unusable when the author is offline.
After you finish, open the result on your device, move keepers into a folder you control, and only then close this tab. That sequence keeps half-written files and lost downloads out of your next session.
If something fails, change one variable at a time: the input file or URL, the output format choice, or the network you are on. Note what changed so the next attempt is a measured test rather than a random retry.
Questions about local encryption
Does Vidzilla upload my file to encrypt it?
No. This tool runs in your browser with the Web Crypto API. Files and keys stay on your device for the encrypt and decrypt pass.
Which algorithm should I pick?
Choose AES when you are encrypting a new file. Match the original algorithm when you decrypt an older output from this page.
What happens if I lose the key?
The encrypted file cannot be recovered through this page. Store the key in a password manager or another safe place before you discard plaintext.
Do I need an account?
No. Local encrypt and decrypt run without signing in.
Can I encrypt a folder of files in one click?
Encrypt one file at a time here. Zip the folder first if you need a single archive, then encrypt that archive.
Is this the same as full-disk encryption?
No. This page protects files you select. Operating-system disk encryption covers the whole drive separately.