187 reviews
  • You answered: "The addon does not report based on URL but on the JavaScript that is executed on the site."

    So I have a suggestion: This behaviour "accuse" almost every Url / Website, to spy via Canvas-technic.
    Can you reduce this warning to only sites, where that Canvas-technic is really used?
    I would say that differentiating between fingerprinting and legitimate use of the readout API is impossible without a full static code analysis which would make your browser incredible slow - especially while looking at PDFs.

    The notification also is not meant to be an accuse but an information that a call to the readout API did not return the real values but some faked ones.

    So I'm sorry but the answer is "No".
  • Problem fixed by a development version made available by author at github.

    Raising star rating to 5.
  • Great plugin.
    Can you please update latest release for Palemoon browser ?

    Thanks
  • Essential addon for everybody, works great & easy to use, with fake readout api mode, it doesn't break websites.
  • Works great in Firefox. Unfortunately it's not available for Thunderbird. Hopefully that will be fixed soon!
    Thank you for your rating.

    Can you please open an issue on https://github.com/kkapsner/CanvasBlocker/issues where you explain why you need it in Thunderbird. Thank you.
  • I can't answer to my own thread, so here i have a question from the https://addons.mozilla.org/de/firefox/addon/canvasblocker/reviews/660262/ thread.
    Is the Components.utils.exportFunction realy needed? If yes, maybe you can help us: http://forum.palemoon.org/viewtopic.php?p=45352#p45352
  • Soundcloud doesn't work with this Add-on
    The site works fine with one of the "Readout-API"-modes.
    The "block all"-mode interferes with the loading icon...
  • Since there is no option to disable canvas functionality directly in the browser, this add-on is essential for everyone concerned about online privacy.

    I'm using it alongside Adblock Edge, NoScript and Self-Destructing Cookies.
  • Excellent add-on, shows all the sites that try to manipulate canvases, and stops them from doing it. You can also set a whitelist, note that some Google pages are whitelisted by default!

    One bug: this add-on causes a memory leak in Firefox 32: after browsing for a while you will see in about:memory a lot of ghost windows, which also make the browser laggy as the garbage collector repeatedly tries to clean them up. Temporarily disable this add-on (no restart required) and the GC will shortly get rid of them. This should be fixed though.
    Thank you for the Review.

    I will try to hunt down the memory leak.

    The google-Page that is white listed should be related to google-maps. But I added a note in the description.

    EDIT: in version 0.1.3 the memory leak should be gone.
  • I love this so far, Canvas fingerprinting definitely needs to be addressed. The one thing I would change is having a gui allowing us to whitelist or blacklist domains as we encounter them. Something similar to Noscript maybe. At least having an icon we can place would be great. (unless there's one I can't see, I'm on palemoon. If that is the case, disregard this comment)

    Also, it would be nice if instead of a popup in the middle of the screen, the warning would be a more subtle bubble in the corner, similarly to self-destructing cookie's messages. Again, having options to whitelist or blacklist for the future on this message would be great.

    As far as the canvas elements themselves, more information would be great. Things such as the source of the script, maybe with a "details" button with more technical info.

    Overall though, great addon. Good luck in it's development and thanks for addressing a privacy issue. I hope my suggestions are helpful. I do understand that this is an early version and some of those Gui elements might be planned already for the future, so no worries there. :)

    Browser: Palemoon 24.7.1
    OS: Linux Mint 17, Xfce
  • Ich habe gerade verwendet, um dieses in Firefox. Es funktioniert perfekt! Absolut gar nichts "Browserleaks"! Tausend Dank!
  • Good Idea, but dont work
    tested himself: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Canvas_tutorial/Drawing_shapes

    u see all image

    ok now fixed on version 0.1.1

    but now i get a loop of asked, i turn of the ask, and all fine now
    Thank you for the comment.
    This issue is fixed in Version 0.1.1 now you are asked for every.
    Please update and recheck with your firefox.

    Great - I'm currently working on a better ask procedure. It now opens a prompt for every that is used on the site... which can be many.