CanvasBlocker

Name: CanvasBlocker
Rating: 4.5806 (484 reviews)
Author: kkapsner

By: kkapsner

Alters some JS APIs to prevent fingerprinting.

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Features & Capabilities

CanvasBlocker is a powerful Chrome extension designed to protect your privacy by altering specific JavaScript APIs that websites use to fingerprint users. It targets common fingerprinting vectors such as canvas 2D, webGL, audio, history, DOMRect, and more, allowing you to block these APIs entirely or provide fake data to avoid consistent fingerprinting.

Users can customize protection with multiple modes including blocking everything, allowing only whitelisted sites, or an optimized fake mode that balances usability and privacy. The extension also advises maintaining only one fingerprinting protection addon active to avoid performance issues. CanvasBlocker is ideal for users seeking enhanced privacy without sacrificing browsing functionality.

User Growth & Download Statistics

Add-on

By:

Daily users:

Rating:

Version:

1.12 Last updated: 2026-02-13

Version code:

6146768

Creation date:

2014-08-04

Risk:

Permissions:

<all_urls>
storage
tabs
webRequest
webRequestBlocking
contextualIdentities
cookies
privacy

Content scripts matches:

<all_urls>

Size:

468.55KB

URLs:

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-17

Compare stats and ranking:

Ranking

# 367 ▼ 2

Other rankings

#22 in Privacy & Security

#1 in prevent keyword 37

#3 in website blocker keyword 63

#6 in scan keyword 22

#6 in writer's block keyword 12

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For Developers

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Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

kkapsner

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/canvasblocker/

User Reviews

CanvasBlocker is highly praised for its fingerprinting protection and privacy gains; most reviews cite its ability to change fingerprints on refresh and customizable site-specific settings that keep browsing smooth. It is generally described as lightweight and easy to test. However, a minority report inconsistent results (fingerprints not changing or fingerprint checks indicating no effect) and a few isolated complaints about site breakage on certain services. Overall, it’s viewed as a valuable privacy tool with occasional reliability caveats.

Pros

Changes the fingerprint on every refresh, reducing tracking.
Strong privacy/anti-fingerprinting enhancement; widely appreciated and essential for anonymity.
Per-site customization with adjustable strictness to prevent breakage.
Lightweight, runs in the background and doesn't slow browsing.

Cons

Inconsistent effectiveness; some users report fingerprints don't change or tests show no effect.

Recent reviews

by Fi*****, 2026-06-02

非常简单高效的扩展，每次刷新页面都能改变浏览器指纹，再也不用担心被追踪了

by Ri*****, 2026-05-26

by Sü*****, 2026-05-19

View all user reviews ›

Is CanvasBlocker 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.

CanvasBlocker requires some sensitive permissions that could impact your browser and data security. 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.
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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.

CanvasBlocker has earned a good reputation and can be trusted.

Risk likelihood analysis details

Medium This extension has medium user count. Unpopular extensions may not be stable or safe.
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