Encrypt or decrypt text and files with repeating-key byte transformation. Use your own key or apply a generated 512-bit key, then save results locally with clear file suffixes.
Encryption is the process of converting readable text or files into an unreadable format using a secret key, ensuring that only authorized recipients can access the original content. Decryption reverses this process, transforming the scrambled data back into its original form with the correct key. Whether you need to protect sensitive messages, secure confidential documents, or safely share private information, encryption and decryption are essential tools for maintaining digital privacy and data security.
Yes. All processing takes place entirely within your web browser. Your text, files, and encryption keys are never transmitted to any server, ensuring complete privacy and security of your data.
Without the exact key used during encryption, it is not possible to decrypt your data. We strongly recommend using the Export Key feature to save your key to a secure location immediately after encrypting any important content.
You can encrypt and decrypt any file type, including documents, images, videos, compressed archives, and more. The tool processes files at the byte level, so the format does not matter. Encrypted files are saved with a "-enc" suffix, and decrypted files with a "-dec" suffix.
Absolutely. You can type any key you prefer into the key field. However, longer and more complex keys provide stronger encryption. The suggested 512-bit key offers a high level of security and is recommended for sensitive data.
Once the page has loaded in your browser, the encryption and decryption functionality works without an active internet connection. Since all processing is performed locally, you can use the tool offline after the initial page load.
Encryption is the process of transforming readable data — called plaintext — into an unreadable scrambled form called ciphertext, using a mathematical algorithm and a secret key. Only someone who possesses the correct key can reverse the process and recover the original plaintext. Encryption is the foundation of modern digital security: it protects messages in transit, secures stored passwords, authenticates software updates, and ensures that sensitive data remains private even if it is intercepted or stolen. Without encryption, every email, login, bank transaction, and private message would be visible to anyone monitoring network traffic.
It is important to understand how encryption differs from two related but distinct concepts: encoding and hashing. Encoding, such as Base64, transforms data into a different representation for compatibility purposes — it is not a security measure and is trivially reversible without any key. Hashing, used for passwords and data integrity verification, is a one-way process: the same input always produces the same output, but the original input cannot be recovered from the hash. Encryption, unlike hashing, is designed to be reversible — but only by someone with the correct key. Confusing these three concepts is a common source of security vulnerabilities in applications.
This browser-based encryptor uses industry-standard algorithms such as AES (Advanced Encryption Standard) to encrypt and decrypt text directly in your browser. Your data never leaves your device — the encryption happens entirely in JavaScript on your local machine, meaning no server sees your plaintext or your key. This makes it suitable for a wide range of practical privacy tasks, from encrypting a personal note before storing it in a shared location to securely transmitting a password or API key to a colleague.
AES (Advanced Encryption Standard) is a true encryption algorithm: it uses a secret key to scramble data in a way that is computationally infeasible to reverse without the key. The output looks like random noise unless you know the key. Base64 is not encryption — it is an encoding scheme that converts binary data into a text-safe format using 64 printable ASCII characters. Base64 is trivially reversible by anyone without any key at all. It exists for compatibility, not security. A common mistake is Base64-encoding sensitive data and believing it is protected. If you need real security, use AES. If you just need to safely transmit binary data over a text channel, use Base64.
Browser-based encryption using the Web Crypto API — which this tool relies on — is considered safe for many practical use cases. The actual encryption happens entirely in JavaScript within your browser's sandboxed environment, and no data is transmitted to any server. However, browser encryption has meaningful limitations: your data's security is only as strong as your key's secrecy, and the browser itself could theoretically be compromised by malicious extensions or a man-in-the-browser attack. For extremely sensitive data — medical records, legal documents, classified information — use dedicated, audited encryption software such as GPG or VeraCrypt rather than any web tool.
Symmetric encryption uses the same key for both encryption and decryption. If you encrypt a message with the key "mysecretkey", the recipient must also have "mysecretkey" to decrypt it. AES is the most widely used symmetric encryption algorithm, and it is the standard used by this tool. The challenge with symmetric encryption is securely sharing the key with the recipient — if the key is intercepted, the encryption is compromised. Asymmetric encryption, by contrast, uses a public key for encryption and a private key for decryption, solving the key-exchange problem but at higher computational cost. Most real-world secure systems use asymmetric encryption to exchange a symmetric key, then use symmetric encryption for the actual data.
With strong modern encryption like AES-256, losing the key means the data is effectively unrecoverable. There is no backdoor, no master key, and no way to brute-force a 256-bit key with any computing power available today or in the foreseeable future — the number of possible keys is greater than the number of atoms in the observable universe. This is by design: the security of the system depends entirely on the key's secrecy and the impossibility of guessing it. Always store your encryption keys securely — in a password manager, written down in a secure physical location, or derived from a strong passphrase you can reliably remember.
Password protection on a file (such as a password-protected PDF or ZIP file) does not always mean the file is strongly encrypted. Some password protection schemes simply add a simple lock that can be bypassed with freely available cracking tools. True encryption transforms the actual data so that it cannot be read without the key, regardless of the application used to open it. When a file is encrypted with AES-256, the ciphertext is mathematically secure even if an attacker has unlimited access to the file. Always verify that the software you use for password protection applies genuine encryption — the product documentation should specify the algorithm and key length used.
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