Password Vault (Local)

Encrypted password storage using AES-256 with a master password. All data in localStorage - zero-knowledge, no server.

How to Use Password Vault (Local)

1

Set master password

Create a strong master password to encrypt your vault.
2

Add credentials

Store website URLs, usernames, and passwords securely.
3

Search and copy

Find entries quickly and copy passwords without revealing them.

Tested tool guide Tested browser tools Checked August 16, 2026

What Password Vault (Local) does and how it behaves

This tool keeps a list of passwords in an encrypted vault stored in your browser's localStorage. You set one master password; it is used to derive the key that encrypts every entry with AES-256 before anything touches storage, and entries are decrypted back to plaintext only in memory while the vault is unlocked. Nothing is sent to a server - the site never sees your master password or your stored passwords. The surprise most people hit: there is no password reset. If you forget the master password, the vault's contents are unrecoverable by design.

How the result is produced

Encrypt-before-store

Every entry you add - site, username, password, notes - is encrypted with AES-256 using a key derived from your master password before it is written to localStorage. The plaintext key exists only in the browser's memory while the vault is unlocked; persistent storage only ever holds ciphertext, so inspecting localStorage directly shows unreadable data, not your passwords.

Local-only storage

localStorage is scoped to this exact origin, browser, and device profile. There is no account, sync service, or cloud backup - clearing site data, using a different browser, switching devices, or browsing in a private window that discards storage on close all mean the vault and everything in it is gone unless you exported it yourself first.

Good uses

Keeping a small personal password list encrypted at rest on a computer where you don't want to install a browser extension
Storing credentials for a handful of accounts without creating an account with a third-party password manager vendor
Testing or demonstrating a zero-knowledge, client-side encryption pattern where the master password never leaves the browser

Limits and checks

Forgetting the master password destroys access permanently. Because the master password is never sent anywhere and never stored in recoverable form, there is no 'forgot password' flow - losing it means losing every entry in the vault, with no exception.
The vault lives only in this browser's localStorage for this exact site origin and device profile. It does not sync to your phone, another computer, or even a different browser on the same machine, so switching devices or clearing browser data starts you over.
Encryption strength depends on the master password you actually choose - a short, guessable, or reused password weakens the AES-256 layer meant to protect everything else. localStorage is also readable by any script running on the same origin, so a compromised browser extension or an XSS bug elsewhere on the page could expose it.

Common questions

Can I open my vault on my phone or another computer?

Not unless the tool gives you an explicit export/import step you run yourself. localStorage is per-browser, per-device, and per-origin, so a vault created on one machine is not visible from another - there is no server-side copy to sync from.

Is this safer than my browser's built-in password manager?

Not necessarily - it trades browser-vendor sync and breach-alert features for a self-contained AES-256 vault under a password only you know. Whether that's a net gain depends on whether you trust your own master password discipline more than a vendor's account security.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.