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Security

File Encrypt & Decrypt

Encrypt and decrypt files securely using AES-256-GCM directly in your browser — no uploads, no servers.

Drop a file here

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Key derived using PBKDF2 with 100,000 iterations and a random salt.

All file encryption runs 100% locally in your browser. Files are never uploaded to any server. The password and cryptographic keys remain on your device.

Protecting sensitive files — whether they are confidential documents, private images, database backups, or configuration archives — is an essential part of modern digital security. A file encryption and decryption tool allows you to secure your data with strong cryptography before storing it in the cloud, sending it over email, or transferring it via USB drives. Our free browser-based utility uses AES-256-GCM, the same encryption standard trusted by governments and financial institutions worldwide, and processes everything locally in your browser.

File Encryption vs File Protection

Many people rely on folder passwords, ZIP archive passwords, or operating-system-level permissions to protect their files. However, these methods often use weak encryption or no encryption at all. A ZIP password, for example, only protects the file listing — the actual contents may still be recoverable without the password.

True file encryption transforms the file's binary data into an unrecognizable format using a cryptographic algorithm and a secret key. Without the correct password, the encrypted file is mathematically impossible to decrypt, regardless of who accesses it.

How AES-256-GCM File Encryption Works

Our tool uses the Advanced Encryption Standard (AES) in Galois/Counter Mode (GCM) with 256-bit keys — the gold standard for file encryption. Here is the complete process:

1. Key Derivation (PBKDF2)

Your password is combined with a cryptographically random 128-bit salt and hashed 100,000 times using SHA-256. This creates a high-entropy 256-bit AES key and makes brute-force attacks infeasible.

2. Random IV Generation

A unique 96-bit initialization vector (IV) is generated for every encryption. This ensures that encrypting the same file twice produces completely different output, preventing pattern analysis.

3. Authenticated Encryption

AES-256-GCM encrypts the file data in 16-byte blocks while simultaneously computing an authentication tag. This tag verifies that the ciphertext has not been tampered with — any modification causes decryption to fail immediately.

4. Self-Contained Output

The salt, IV, original filename, and ciphertext are packaged into a single .enc file. This means you only need the password to decrypt — no separate metadata or configuration files required.

When to Use File Encryption

Cloud Backup Protection

Encrypt sensitive files before uploading to Dropbox, Google Drive, or iCloud. Even if your cloud account is compromised, your files remain secure.

Email Attachments

Send encrypted files over email with the password shared through a separate channel (phone, messaging app) for defense-in-depth security.

Portable Storage

Encrypt files on USB drives before travelling. If the drive is lost or stolen, your data remains inaccessible without the password.

Database & Config Backups

Protect database dumps, environment files, and API key archives with strong encryption before storing them in backup systems or CI/CD pipelines.

Frequently Asked Questions

Can someone decrypt my file without the password?
No. AES-256-GCM is mathematically secure. Without the correct password, decrypting the file is computationally infeasible — brute-forcing a 256-bit key would take trillions of years with current technology.
What happens if I forget the password?
There is no password recovery option — by design. The encryption key is derived directly from your password, and no backup or recovery mechanism exists. Store your password in a password manager and consider keeping a secure backup.
What file types can I encrypt?
Any file type — documents (PDF, DOCX), images (JPG, PNG), archives (ZIP, TAR), databases (SQLite, SQL), configuration files (YAML, JSON, ENV), or binaries. The tool processes raw bytes and preserves the original filename for decryption.
Is there a file size limit?
Since all processing happens in browser memory, the practical limit depends on your device's available RAM. For most modern computers, files up to 500MB should work reliably. Larger files may require a device with more memory.

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