Encrypted Note Taker - Online Write & Encrypt in Browser

Browser-side encryption means all cryptographic operations (encrypting and decrypting your notes) happen locally on your device, inside your web browser. Your plaintext notes and passwords are never transmitted over the internet or stored on any remote server. This gives you full control over your data and eliminates the risk of server-side data breaches exposing your sensitive information. Even we, as the tool provider, cannot access your encrypted notes.

We use AES-256-GCM (Advanced Encryption Standard with 256-bit key in Galois/Counter Mode), which is one of the most trusted encryption standards worldwide. It is approved by NIST for securing top-secret government documents and is widely used by banks, military organizations, and tech companies. GCM mode provides both confidentiality and integrity — meaning not only is your data secret, but any tampering with the encrypted text will be detected during decryption. Combined with PBKDF2 key derivation (100,000 SHA-256 iterations) and a random 128-bit salt, your notes are protected against brute-force attacks.

No. Absolutely nothing leaves your browser. The entire encryption and decryption process runs 100% client-side using the browser's native Web Crypto API. There are no API calls, no analytics tracking your input, and no background data transfers. You can even disconnect from the internet after loading this page, and the tool will continue to work perfectly offline. Your privacy is guaranteed by design.

If you lose or forget your password, your encrypted notes cannot be recovered. There is no backdoor, no password reset mechanism, and no recovery key. This is intentional — true security means that only the person who knows the password can access the data. We strongly recommend using a password manager to store your encryption passwords securely, or writing them down in a physically secure location. Consider using a memorable but strong passphrase (e.g., four or more random words).

You can safely share the encrypted output text through any channel — email, messaging apps, or cloud storage — because without the password, the encrypted text is useless to anyone who intercepts it. However, you must share the password through a separate, secure channel (e.g., a phone call, encrypted messaging app like Signal, or in person). Never send the password and the encrypted note through the same communication channel. The recipient can then paste the encrypted text into this tool and use the password to decrypt it.

A strong password for encryption should be:
• At least 12 characters long (longer is better)
• A mix of uppercase and lowercase letters, numbers, and symbols
• Not a common word or phrase found in dictionaries
• Unique — never reuse passwords across different services

For best results, consider using a passphrase: a sequence of 4-6 random words (e.g., "correct horse battery staple"). Passphrases are both secure and easier to remember. You can also use the built-in password generator (wand icon) to create a cryptographically random password.

PBKDF2 (Password-Based Key Derivation Function 2) is a cryptographic algorithm that transforms a human-readable password into a secure encryption key. It applies a hash function (SHA-256) repeatedly (100,000 times in our implementation) along with a unique random salt. This process, called key stretching, makes it extremely computationally expensive for attackers to try millions of password guesses (brute-force attacks). Even with powerful hardware, each password guess requires significant time, dramatically slowing down any cracking attempt. The random salt ensures that identical passwords produce different encryption keys.

Yes! Once the page has loaded, all functionality works completely offline. The encryption and decryption rely solely on the Web Crypto API built into your browser — no internet connection is required. You can save the page for offline use, or even use it on a device with no network access for maximum security. This also means your data is safe from any network-based attacks or monitoring.

The encrypted output is a Base64-encoded string that contains three concatenated components:
• 16-byte random salt — used for PBKDF2 key derivation
• 12-byte random IV (nonce) — initialization vector for AES-GCM
• Ciphertext + 16-byte authentication tag — the actual encrypted data with integrity protection

This format ensures that each encryption of the same note with the same password produces a completely different output, preventing pattern analysis. The authentication tag guarantees that any modification to the encrypted text will be detected and rejected during decryption.

Unlike many "encrypted note" apps that store your data on their servers (even if encrypted at rest), this tool operates entirely locally with zero server interaction. Key advantages:
• No account required — no email, no sign-up, no tracking
• No data storage — we never see or store your notes
• Transparent — you can inspect the page source to verify the encryption implementation
• Portable — the encrypted text can be stored anywhere (local files, cloud drives, messaging apps)
• No vendor lock-in — the encryption format is standard and can be decrypted by other tools if needed
The trade-off is that you are fully responsible for managing your passwords and encrypted data — there is no recovery mechanism.