Secure Notes (Encrypted)
Store your sensitive thoughts with AES-256 encryption. Data is locked by your password.
What is Secure Notes (Encrypted)?
Secure Notes is a browser-based encrypted note-taking tool that stores your notes using AES-256 encryption before saving them to localStorage. Unlike standard note apps that store plaintext in the browser or sync to cloud servers, Secure Notes encrypts each note with a passphrase before saving — so even if someone accesses your browser's storage, they cannot read your notes without the correct key.
Your notes are encrypted locally, stored locally, and decrypted locally. No plaintext ever leaves your device at any stage.
How to Use Secure Notes
Creating and reading encrypted notes involves these steps:
- Enter a passphrase in the Encryption Key field. This key is used to encrypt and decrypt your notes — remember it carefully.
- Type your note content in the Note editor field.
- Click "Save & Encrypt" to encrypt the note with your passphrase and store it in localStorage.
- To read a saved note, select it from the notes list, enter your passphrase, and click "Decrypt & View".
- Use "Delete Note" to permanently remove a note from localStorage.
- All notes are stored as AES-256 ciphertext — unreadable without the correct passphrase.
Key Features
- AES-256 Encryption: Each note is encrypted using AES-256-GCM before storage — the same algorithm used in enterprise security.
- Passphrase-Based Access: Notes are locked behind a user-defined passphrase that is never stored or transmitted.
- Encrypted LocalStorage: Even if browser storage is inspected, notes appear as random ciphertext.
- Multiple Notes: Create and manage multiple separate encrypted notes with individual access control.
Common Use Cases
This tool is helpful for the following tasks:
- Sensitive Personal Notes: Storing private journal entries, account recovery codes, or personal identification details.
- Secure Credential Storage: Keeping temporary password notes, Wi-Fi credentials, or API keys in an encrypted format.
- Confidential Work Notes: Writing sensitive project notes or client information that should not be stored in plaintext.
Frequently Asked Questions
What happens if I forget my passphrase?
There is no recovery mechanism. Notes are encrypted with your passphrase using AES-256. Without the exact passphrase, the encrypted ciphertext is unrecoverable. Store your passphrase securely.
Can I use a different passphrase for each note?
Yes. Each note is encrypted independently, so you can use different passphrases for different notes for additional security compartmentalization.
Are my notes synced to the cloud?
No. All notes are stored exclusively in your browser's localStorage on the current device. There is no sync, no backup, and no server.
What if I clear my browser data?
Clearing site data for 99tool.in will delete your encrypted notes. Export important notes as files before clearing browser storage.
Privacy & Data Note
All note content is encrypted using AES-256-GCM before storage. Your plaintext notes, passphrase, and ciphertext never leave your device. All encryption and decryption runs entirely inside your browser using the Web Crypto API.
Frequently Asked Questions
There is no recovery mechanism. Notes are encrypted with AES-256 using your passphrase as the key. Without the exact passphrase, the data is mathematically unrecoverable. Use a password manager to store your passphrase safely.
No. All notes are stored exclusively in your browser's localStorage on the current device. There is no cloud sync, no server, and no backup. Clear browser data with caution.
Yes. Each note is encrypted independently, so you can assign a unique passphrase to each note for compartmentalized access control.
🔒 AES-256 Encrypted Notes. No cloud. No server. Only you can read your notes. Last updated: April 10, 2026.