This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

How to display correct timezone while keeping privacy.resistFingerprinting=TRUE ?

  • 6 replies
  • 1 has this problem
  • 19 views
  • Last reply by cor-el

more options

Hi all,

I've set privacy.resistFingerprinting to true, and now all clocks displayed in browser show UTC (not my timezone). Is there a way I can change my timezone while retaining privacy.resistFingerprinting=true ?

A few notes: • My OS preferences display the correct timezone. • I've seen CanvasBlocker mentioned in a few support posts related to this issue – is there something I can tweak in that add-on that will solve my problem?

Thanks in advance!

Hi all, I've set privacy.resistFingerprinting to true, and now all clocks displayed in browser show UTC (not my timezone). Is there a way I can change my timezone while retaining privacy.resistFingerprinting=true ? A few notes: • My OS preferences display the correct timezone. • I've seen CanvasBlocker mentioned in a few support posts related to this issue – is there something I can tweak in that add-on that will solve my problem? Thanks in advance!

All Replies (6)

more options

The idea behind reporting your time zone as UTC is to prevent websites from knowing your time zone. You probably can use an add-on or user script to correct the times, but the page can be aware of such changes, so you are potentially giving up a little bit of information there.

Assuming you were looking for an add-on, I'm not aware of one, but it wouldn't surprise me if other people using privacy.resistFingerprinting have found one by now.

more options

Note that "Resist Fingerprinting" also changes the user agent to Firefox 68 (ESR) and affects the window dimensions that are rounded to fixed values apart from changing the timezone to UTC. You will normally still be unique, but websites probably can't get your real values.

You can search for extensions that block or modify specific fingerprinting tests.

more options

@jscher2000 I found some add-ons that allow me to spoof my timezone, but changing resistFingerprinting back to false will still expose the rest of my information.


Moving on to user scripts, as far as I can tell, there’s nothing on Greasy Fork that would solve my issue. But after some digging, I discovered I can change my user agent manually on this page. If I created general.useragent.override, would that get me on the right track? I’m hesitant to start messing around with this and cause more issues.




Although I’d like to avoid it, I can live with reporting my timezone in order to fix this issue, but ideally not any of the other information in my fingerprint.

more options

What I think is needed is an extension or user script that reads the UTC times in the page and recalculates them to the time you want to see. I saw one that only works if the time zone is stated with the time (so it know how many time zones to shift).

I realize now that I think about this more that times might be in different places on different pages, so any extension or user script is going to require some "training" to understand where to look. It might be more complicated than I originally thought.

more options

Hmm, sounds like that’s quite a bit above my skill level. For a workaround, would you say CanvasBlocker or CanvasDefender would be as effective as resistFingerprinting=true? I'm not clear on the differences between blocking something with an add-on versus at the browser level.

By the way, I appreciate all the help. You've come up several times in my quest to solve this issue, and it looks like I'm talking to the right person :)

more options