If you encounter any problems please check the FAQ first. Please report issues and feature requests at https://github.com/kkapsner/CanvasBlocker/issues
IMPORTANT: you should only have ONE addon/setting set that protects an API. Otherwise you could face massive performance issues. (E.g. EclipsedMoon for Palemoon has 'canvas.poison' which is known to cause issues: https://github.com/kkapsner/CanvasBlocker/issues/253#issuecomment-459499290)
But setting privacy.resistFingerprinting to true and/or using the new fingerprinting protection introduced with Firefox 67 is fine.
Protected "fingerprinting" APIs:
- canvas 2d
- window (disabled by default)
- navigator (disabled by default)
More information on fingerprinting can be found at:
- <canvas>: http://www.browserleaks.com/canvas
- https://audiofingerprint.openwpm.com/ (very poorly written = slow)
The different block modes are:
- fake: Canvas Blocker's default setting, and my favorite! All websites not on the white list or black list can use the protected APIs. But values obtained by the APIs are altered so that a consistent fingerprinting is not possible
- ask for permission: If a website is not listed on the white list or black list, the user will be asked if the website should be allowed to use the protected APIs each time they are called.
- block everything: Ignore all lists and block the protected APIs on all websites.
- allow only white list: Only websites in the white list are allowed to use the protected APIs.
- block only black list: Block the protected APIs only for websites on the black list.
- allow everything: Ignore all lists and allow the protected APIs on all websites.
Report this add-on for abuse
If you think this add-on violates Mozilla's add-on policies or has security or privacy issues, please report these issues to Mozilla using this form.
Please don't use this form to report bugs or request add-on features; this report will be sent to Mozilla and not to the add-on developer.
This add-on can:
- Access your data for all websites
- Read and modify privacy settings
- Access browser tabs
- added notice for privacy.resistFingerprinting
- added container specific navigator settings
- error when exporting function with name "top"
- tabs opened with window.open broke when the parent tab was reloaded/closed
- importing settings file with an very old storage version did not work at all
- if a data URL is blocked the page action button does not appear