Prevent Pwned Passwords

Prevent Pwned Passwords

Checks password hashes against Have I Been Pwned and displays a notification if the hash has been leaked in a breach.

What is Prevent Pwned Passwords?
Prevent Pwned Passwords is a Firefox add-on that checks password hashes against Have I Been Pwned database and alerts users if their password has been compromised in a breach. It securely hashes passwords and does not transmit any identifiable information.
Users: 74 ▲ 2
Rating: 3.00 (3)
Version: 1.0.1resigned1 (Last updated: 2024-04-25)
Creation date: 2017-10-29
Weekly download count: NaN
Firefox on Android: Yes
Risk impact: High risk impact
Risk likelihood: Moderate risk likelihood
Manifest version: 2
  • notifications
  • storage
  • contextMenus
  • tabs
Size: 53.32K
Stats date:

Other platforms

Not available on Chrome
Not available on Edge
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Prevent Pwned Passwords helps make sure you don't use any password that's known to have been part of a data breach. If you try to use a password that's known to have been compromised, you'll get an alert.

You can choose to run it whenever you enter a password on any site, whenever you enter a password on a "Create Account" page, or only when you choose to check a password from a context menu. You can also whitelist sites, giving you greater control over what passwords are checked.

This extension hashes your password and securely checks that hash against a database of hashes known to be breached. If it's been involved in a past breach (of any account across hundreds of sites), it notifies you so you can change your password.

Note that the only data ever transmitted is a password hash. We never send a clear-text password or any identifiable information like a username or a URL.

This extension uses the Have I Been Pwned service.

Risk impact

Prevent Pwned Passwords is risky to use as it requires a number of sensitive permissions that can potentially harm your browser and steal your data. Exercise caution when installing this add-on. Review carefully before installing. We recommend that you only install Prevent Pwned Passwords if you trust the publisher.

Risk likelihood

Prevent Pwned Passwords is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

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