NSC Blocker
The NSC response header defines how websites can communicate that their content isn't safe, for example when it contains adult content. The header is defined in an experimental specification and implemented on the client side with this add-on.
English
Español
Français
Português
日本語
简体中文
한국인
Features & Capabilities
User Growth & Download Statistics
Manifest V2 Add-on
- By:
- Safe Internet Initiative
- Daily users:
- -
- Rating:
- 5.00 (1)
- Version:
- 1.2 Last updated: 2022-03-29
- Version code:
- 5384759
- Creation date:
- 2022-03-26
- Risk:
- Moderate risk impact Low risk likelihood
- Permissions:
- webRequest
- webRequestBlocking
- storage
- <all_urls>
- webRequest
- Size:
- 99.87KB
- Email:
- ad*****@safe-internet.org
- URLs:
- Website
- Full description:
- See detailed description
- Source:
- Firefox Add-ons Store
- Data ingested on:
- 2026-06-19
- Compare stats and ranking:
- NSC Blocker vs BlockNSFW – Porn & Adult Content Filter
- NSC Blocker vs content-web-blocker
- NSC Blocker vs CSPBlocker
For Developers
Contact the developer
Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.
Is NSC Blocker Safe?
Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.
NSC Blocker requires a few sensitive permissions. Exercise caution before installing.
Risk impact analysis details
- Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- High ****** *** ********* ** ******* *** ******* ******* ** ****** *** *** ******** ******
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.
NSC Blocker has earned a fairly good reputation and likely can be trusted.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
- Good **** ********* *** **** **** *******
Extension Guard
Discover every extension in use, analyze risks, and enforce blocking policies with Extension Guard
Secure Your Browser Upgrade to see full risk analysis details
Best NSC Blocker Alternatives
Here are some Firefox add-ons that are similar to NSC Blocker:
BlockNSFW – Porn & Adult Content Filter
Monolab Co.
2K 4.32 
(19) 
content-web-blocker
frroossst
- 0.00 (0) 
CSPBlocker
Jeurissen Apps
34 4.00 (2) 
Content Safety Lock
Dan Wright
2 0.00 (0) 
Precision Site Blocker
F168
- 0.00 (0) 
NSFW Content Blocker
Nayaneesh Kumar Mishra
2 1.00 (3) 
Enhanced Unsafe Site Blocker
Delia
- 0.00 (0) 
DNS Medic
jstoneky
6 5.00 (1) 
Port Authority
Hacks and Hops
24K 4.64 (74) 
Simple Website Timed Blocker
ni6hant
7 5.00 (1) 
JavaScript Blocker
Burak Unver
31 0.00 (0) 
Simple Site Blocker
Big Developer
26 4.50 (4)