AES (Advanced Encryption Standard) is a symmetric encryption algorithm — the same key is used for both encryption and decryption. It's the global standard for securing sensitive data, trusted by governments, banks, and organizations worldwide. AES operates on fixed-size blocks (128 bits) and supports key sizes of 128, 192, or 256 bits. AES-256 is considered quantum-resistant and virtually unbreakable with current technology. This tool uses AES-GCM (Galois/Counter Mode) by default, which provides both confidentiality and authentication, protecting against tampering.

RSA (Rivest-Shamir-Adleman) is an asymmetric encryption algorithm that uses a key pair: a public key for encryption and a private key for decryption. You can freely share your public key with anyone who needs to send you encrypted messages, while keeping the private key secret. RSA is ideal for scenarios where secure key exchange is needed — like sending encrypted messages to someone without first sharing a password. This tool implements RSA-OAEP (Optimal Asymmetric Encryption Padding) with hybrid encryption, meaning it automatically handles texts of any length by combining RSA with AES.

AES is symmetric (same key encrypts and decrypts), extremely fast, and suitable for encrypting large amounts of data. RSA is asymmetric (public/private key pair), slower, and typically used for encrypting small pieces of data or exchanging symmetric keys. In practice, they complement each other: RSA is often used to securely exchange an AES key (hybrid encryption), and then AES handles the bulk data encryption. This tool implements hybrid RSA encryption automatically — you get the best of both worlds.

AES-GCM (Galois/Counter Mode) is a modern AES mode that provides authenticated encryption. This means it not only encrypts your data but also verifies its integrity — if anyone tampers with the encrypted data, decryption will fail with an error. This protects against chosen-ciphertext attacks and data manipulation. GCM also doesn't require padding, making it simpler and more efficient than CBC mode. For these reasons, AES-GCM is the recommended default in this tool and is widely used in TLS 1.3, VPNs, and modern security protocols.

Absolutely safe. All encryption and decryption operations happen entirely within your browser using the Web Crypto API — a native browser capability. Your plain text, passwords, and keys never leave your device. There is no server communication, no data collection, and no logging. The tool works fully offline once loaded. You can verify this by opening your browser's developer tools (F12) and checking the Network tab — you'll see zero outbound requests during encryption/decryption operations.

Salt (used in key derivation) and IV (Initialization Vector, used in encryption) are random values that ensure security even when encrypting the same text multiple times with the same password. Without them, identical plaintexts would produce identical ciphertexts, leaking information. Salt prevents rainbow table attacks on password-derived keys. IV ensures each encryption produces unique ciphertext. Both salt and IV are safely included in the output (they don't need to be secret) and are automatically extracted during decryption.

• 2048-bit: Fastest generation, adequate for most purposes. Estimated secure until ~2030.
• 3072-bit: Recommended balance of security and performance. Equivalent to AES-128 security level.
• 4096-bit: Maximum security, but slower to generate (may take 5-15 seconds) and produces larger ciphertexts. Overkill for most use cases.

For most users, 3072-bit offers an excellent balance and is the default in this tool.

Encrypted output is Base64-encoded, making it safe to share via text-based channels like email, messaging apps, or copy-paste. For AES: share the encrypted Base64 string and communicate the password through a separate, secure channel (e.g., in person, Signal, or a different medium). For RSA: share the encrypted Base64 string freely — only the holder of the private key can decrypt it. Never share your private key or password through the same channel as the encrypted data.

The Web Crypto API is supported by all modern browsers, including Chrome (37+), Firefox (34+), Safari (11+), Edge (79+), and Opera (24+). It's a W3C standard and the foundation for secure web applications. The API is available in both desktop and mobile browsers, with consistent behavior across platforms. This tool requires no plugins, extensions, or additional software.