File Locker (AES-256)
Military-grade file encryption that never leaves your browser. 100% private and secure.
Drop file here or click to select
Supports all file types up to 100MB
What is the File Locker (AES-256)?
The File Locker is a browser-based tool that encrypts any file using AES-256-GCM — the same military-grade encryption standard used in secure messaging apps and enterprise data protection. Your file is encrypted entirely in your browser using the Web Crypto API. The encrypted output is downloaded as a .locked file that can be safely stored anywhere without risk of unauthorized access.
To decrypt, simply upload the .locked file, enter the same password used during encryption, and download the restored original. The entire process is local — no file data ever reaches a server.
How to Use the File Locker
Encrypting a file involves these steps:
- Click "Choose File" or drag and drop any file (PDF, image, document, ZIP, etc.) into the upload area.
- Enter a strong password in the Password field. This password is used to derive your AES-256 encryption key via PBKDF2.
- Click "Encrypt & Lock" to process the file. Encryption happens locally in your browser's memory.
- Download the encrypted
.lockedoutput file. Store it anywhere — cloud storage, USB, or email. - To unlock, upload the
.lockedfile, enter the same password, and click "Decrypt & Unlock". The original file is restored.
Key Features
- AES-256-GCM Encryption: Authenticated encryption that protects file integrity in addition to confidentiality.
- PBKDF2 Key Derivation: Derives a 256-bit key from your password using 100,000 rounds, making brute-force attacks impractical.
- Universal File Support: Encrypts any file type — documents, images, videos, archives, executables.
- Zero Upload: Files are never transmitted. All processing occurs in browser RAM via the Web Crypto API.
Common Use Cases
This tool is helpful for the following tasks:
- Protecting Cloud Uploads: Encrypting sensitive files before uploading them to Google Drive, Dropbox, or OneDrive.
- Secure USB Storage: Locking files before placing them on a USB drive that could be lost or stolen.
- Confidential Transfers: Sending encrypted files over email or messaging apps where the recipient has your shared password.
Frequently Asked Questions
What file types can I lock?
Any file type — PDF, DOCX, XLSX, JPG, PNG, MP4, ZIP, and more. The tool treats each file as raw binary data, so format is irrelevant.
Is there a file size limit?
No hard limit is set in the tool. In practice, browser memory allows files up to ~100-500MB. For very large files, use desktop encryption software.
Can I recover the file if I forget my password?
No. Zero-knowledge architecture means no password is stored anywhere. Without the exact password, the file is mathematically unrecoverable.
Are my files uploaded to your servers?
Never. All encryption and decryption runs entirely in your browser's RAM. No file data, filename, or password is transmitted to any server.
Privacy & Data Note
All file processing, encryption, and decryption run entirely inside your browser using the Web Crypto API. No file content, filename, or password is transmitted to any server or stored outside your device.
Frequently Asked Questions
Any file type — PDF, DOCX, JPG, MP4, ZIP, and more. The tool treats each file as raw binary data, ensuring universal compatibility across all formats.
No. This tool uses zero-knowledge architecture — no password is stored anywhere. The file is mathematically unrecoverable without the exact password used during encryption.
Never. All encryption and decryption happens locally in your browser's RAM. No file data, filename, or password ever leaves your device.
🔒 AES-256 Encryption. Zero Upload. Your files never leave your device. Last updated: April 10, 2026.