Block Site
A customizable, password-protected website blocker and redirector.
Block Site - Customizable Website Blocker and Redirector Add-on for Firefox
'Block Site' is a Firefox extension providing control over website access. It allows you to block unwanted domains, use wildcard or regex matching, utilize reverse mode to limit access only to selected sites, and redirect blocked hostnames to new destinations. Furthermore, it protects against data leakage by preventing certain hostnames from capturing your network activity. Additional features include timed blocking, custom messages on blocked pages, aut0-closure of blocked tabs, killing pop-ups, and configurable pause and resume options.
Add-on stats
Weekly download count: 2,410
Firefox on Android: No
Risk impact: High risk impact 
Risk likelihood:
Manifest version: 2
Permissions:
- activeTab
- storage
- notifications
- alarms
- contextMenus
- declarativeNetRequestWithHostAccess
- <all_urls>
- webRequest
- webRequestBlocking
Size: 174.83K
URLs: Website
Ranking
# 256 ▼ 1
Other platforms
Not available on Chrome
Not available on Android
Want to check extension ranking and stats more quickly for other Firefox add-ons?
Install
Chrome-Stats extension
to view Firefox-Stats data as you browse the Firefox Browser Add-ons.
Add-on summary
This extension will block access to websites of your choosing. A master password controls all customization options, as well as access to any blocked site. It’s also possible to redirect navigation from one specific website to another.
Preview: https://www.youtube.com/watch?v=maE-gOUSH4c
Features:
- Block unwanted domains.
- Prevent access to a range of websites using wildcard matching or regular expression matching.
- Reverse mode allows access to only some hostnames and blocks access to all others.
- Custom redirection; you can redirect a single blocked hostname to a new destination.
- Display a custom message on blocked pages.
- Time and date based blocking. Only block access to the websites at specified times and dates. This feature can be configured per hostname.
- Protect data leakage. This extension prevents certain hostnames from gathering network activity from your computer, since blocking occurs before any network request is emitted to the server.
- Auto-closes blocked tabs after a period of time.
- Closes annoying pop-ups as soon as the opening request is received.
User reviews
These summaries are automatically generated weekly using AI based on recent user reviews.
Firefox Browser Add-ons does not verify user reviews, so some user reviews may be inaccurate,
spammy, or outdated. Pros
- Simple and effective design for blocking sites
- Easy to toggle on or off
- Helps users stay focused and reduce distractions
- Effective for long-term users who have found it useful
Cons
- Confusing user interface and settings
- Doesn't consistently block websites as intended
- Issues with adding new sites to block or retaining settings after reboots
- Errors when trying to use certain features like the master password
Most mentioned
- UI is confusing and not user-friendly
- Inconsistent performance in blocking websites
- Settings may not save properly or may revert after browser restarts
- Requires trial and error to learn how to use effectively
User reviews
Works just fine for me. Simple and effective, and the "close" option is great. Leaves me staring at my desktop, wondering why I tried to open reddit for the 50th time this hour.
by LH, 2025-01-05
simplistic design. Easy to block and unblock sites.
by surya, 2024-12-21
it does its job, and does it well enough. i've been using it for over 6 months now.
by David, 2024-12-18
Add-on safety
Risk impact
Block Site requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.
Risk likelihood
Block Site has earned a fairly good reputation and likely can be trusted.
Upgrade to see risk analysis details