File Encryptor

What this tool does

File Encryptor encrypts or decrypts any file with a password-derived AES-256-GCM key (via PBKDF2-SHA256), packing the original filename and MIME type into the encrypted container so they’re restored automatically on decryption, using only the browser’s native Web Crypto API, entirely client-side.

Encrypting a file before uploading it somewhere, or before sending it through a channel you don’t fully trust, usually means installing dedicated software; a browser-based tool that never actually uploads the file anywhere removes that friction for a one-off need.

This tool encrypts any file with a password-derived AES-256-GCM key, the same approach as the AES Text Encryption tool, but for binary files, packing the original filename and MIME type into the encrypted container so decrypting it later restores both automatically, with the file processed entirely in your browser from start to finish.

How to use File Encryptor

1. Choose Encrypt or Decrypt mode.
2. Select the File to process.
3. Enter the Password.
4. For encryption, optionally adjust PBKDF2 iterations.
5. Press Encrypt/Decrypt file and download the result.

Tips for better results

• The encrypted output has a .toolew-enc extension appended and is pure binary ciphertext, opening it in anything other than this tool’s decrypt mode will just show unreadable data.
• On decryption, the original filename and file type are restored automatically from the container, so the downloaded file opens correctly in whatever application normally handles that file type.
• As with the text encryption tool, there is no password recovery, if it’s lost, the file is permanently unreadable, which is the intended, necessary trade-off of real encryption.
• The entire file is processed in your browser’s memory; for very large files, available device memory, not just time, can become a practical limiting factor.

Common use cases

• Encrypting a sensitive document before storing it in cloud storage you don’t fully trust.
• Password-protecting a file before sending it through email or a file-sharing service.
• Creating an encrypted backup of an important file for personal archival.
• Testing or demonstrating client-side file encryption without installing any software.

Common mistakes to avoid

• Losing the password with no backup; there is no recovery path for a forgotten password on an encrypted file, so note it down securely (e.g. in a password manager) before encrypting anything important.
• Attempting to open the .toolew-enc file directly in another application; it’s raw ciphertext and will not open correctly anywhere except this tool’s decrypt mode with the right password.
• Trying to encrypt an extremely large file in one go; browser memory limits mean very large files (many gigabytes) may fail or become impractically slow, since the whole file is held in memory during processing.