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"Cookies and Site Data" that are planted by Firefox itself (not websites)

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I have Firefox set to "Always use private browsing mode."

Then, under "Cookies and Site Data," I select "Accept cookies and site data from websites" and also select "Keep until FIREFOX IS CLOSED."

So, I go to a website. Then, before I go to a different website, I close Firefox because I want it to dump EVERYTHING from my visit to the first website. But, because I am healthily paranoid, I double-check to make sure that everything is dumped. But what I find is the following, under "Cookies and Site Data": "Your stored cookies, site data and cache are currently using 168 kb bytes of disk space." Or, the number can be 148 kb. Or 98 kb. What the number is exactly, however, does not matter except for the fact that THE NUMBER IS NOT ZERO!!!

So, I start suspecting that the residual "cookies, site data and cache" are not from the websites I visit, but FROM FIREFOX ITSELF. Sure as hell, they are. How do I know? Because I can open Firefox, clear the "Cookies and Site Data" so the number goes to zero, then close Firefox without ever going to a website. Then, open Firefox again, and guess what? THE NUMBER IS NOT ZERO ANYMORE.

So, would someone please give me a fix that does not involve cleaning the f'ing cache every time I go to a new website.

And if you have the time, maybe you can convince me why a privacy-minded person should not dump Firefox altogether. (Warning: If your argument is going to be "Don't dump Firefox because there's no better alternative," then you can please save your breath.)

Thanks.

I have Firefox set to "Always use private browsing mode." Then, under "Cookies and Site Data," I select "Accept cookies and site data from websites" and also select "Keep until FIREFOX IS CLOSED." So, I go to a website. Then, before I go to a different website, I close Firefox because I want it to dump EVERYTHING from my visit to the first website. But, because I am healthily paranoid, I double-check to make sure that everything is dumped. But what I find is the following, under "Cookies and Site Data": "Your stored cookies, site data and cache are currently using 168 kb bytes of disk space." Or, the number can be 148 kb. Or 98 kb. What the number is exactly, however, does not matter except for the fact that THE NUMBER IS NOT ZERO!!! So, I start suspecting that the residual "cookies, site data and cache" are not from the websites I visit, but FROM FIREFOX ITSELF. Sure as hell, they are. How do I know? Because I can open Firefox, clear the "Cookies and Site Data" so the number goes to zero, then close Firefox without ever going to a website. Then, open Firefox again, and guess what? THE NUMBER IS NOT ZERO ANYMORE. So, would someone please give me a fix that does not involve cleaning the f'ing cache every time I go to a new website. And if you have the time, maybe you can convince me why a privacy-minded person should not dump Firefox altogether. (Warning: If your argument is going to be "Don't dump Firefox because there's no better alternative," then you can please save your breath.) Thanks.

Additional System Details

Application

  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:61.0) Gecko/20100101 Firefox/61.0

More Information

Wesley Branton
  • Top 10 Contributor
649 solutions 5259 answers

Firefox isn't storing any cookies when you open it. The stored data is your cache. Cache is not used for data tracking of any kind, it's simply to make things load faster the next time you load that page. This usually comes from the home page that loads when you open Firefox because that can contain resources that need to be downloaded from the internet.

I examined the network traffic that Firefox uses when it first starts up and the only think that happened on my system was that Firefox checked to see if it had a network connection by connecting to a secure server and then disconnected. However, this interaction would be present in the Firefox cache, unless you start Firefox in offline mode... which doesn't server much purpose.

If there are cookies being stored when Firefox opens up, it's from an extension that you have installed.

Mozilla takes privacy very serious. It's in their DNA and one of the core missions. Mozilla allows you to opt out of statistical data collection and is constantly developing new technology (like the Facebook Container and Tracking Protection) to help protect user privacy.

Firefox isn't storing any cookies when you open it. The stored data is your cache. Cache is not used for data tracking of any kind, it's simply to make things load faster the next time you load that page. This usually comes from the home page that loads when you open Firefox because that can contain resources that need to be downloaded from the internet. I examined the network traffic that Firefox uses when it first starts up and the only think that happened on my system was that Firefox checked to see if it had a network connection by connecting to a secure server and then disconnected. However, this interaction would be present in the Firefox cache, unless you start Firefox in offline mode... which doesn't server much purpose. If there are cookies being stored when Firefox opens up, it's from an extension that you have installed. Mozilla takes privacy very serious. It's in their DNA and one of the core missions. Mozilla allows you to opt out of statistical data collection and is constantly developing new technology (like the Facebook Container and Tracking Protection) to help protect user privacy.

Question owner

Hmm ...

Are you getting paid for this stuff?

Hmm ... Are you getting paid for this stuff?
jscher2000
  • Top 10 Contributor
8801 solutions 71984 answers

Hi bozotheclown0, data from private browsing windows is not written to disk, so it must be some other data not related to your browsing.

When I test that scenario:

  • Set Firefox to "Never remember history" (start up automatically in private browsing mode)
  • Clear Data
  • Exit Firefox and Start Firefox

When I return to the Clear Data dialog, I have 0 cookies and site data, but 235 KB of cached data. (First screenshot.)

When I example the contents of the disk cache, I see this data was Firefox requesting Pocket stores for the home page. (Second screenshot.)

That might explain yours. To check your disk cache, copy/paste the following to the address bar and press Enter to load it:

about:cache?storage=disk
Hi bozotheclown0, data from private browsing windows is not written to disk, so it must be some other data not related to your browsing. When I test that scenario: * Set Firefox to "Never remember history" (start up automatically in private browsing mode) * Clear Data * Exit Firefox and Start Firefox When I return to the Clear Data dialog, I have 0 cookies and site data, but 235 KB of cached data. (First screenshot.) When I example the contents of the disk cache, I see this data was Firefox requesting Pocket stores for the home page. (Second screenshot.) That might explain yours. To check your disk cache, copy/paste the following to the address bar and press Enter to load it: about:cache?storage=disk
Wesley Branton
  • Top 10 Contributor
649 solutions 5259 answers

Helpful Reply

bozotheclown0 said

Are you getting paid for this stuff?

The people who answer questions here, for the most part, are other Firefox users volunteering their time (like me), not Mozilla employees or Firefox developers.

So to answer your question, no I am not paid. I am simply a volunteer who believes in and wants to support Mozilla's mission to make the internet a better place.

''bozotheclown0 [[#answer-1127683|said]]'' <blockquote>Are you getting paid for this stuff? </blockquote> The people who answer questions here, for the most part, are other Firefox users volunteering their time (like me), not Mozilla employees or Firefox developers. So to answer your question, no I am not paid. I am simply a volunteer who believes in and wants to support Mozilla's mission to make the internet a better place.
cor-el
  • Top 10 Contributor
  • Moderator
17591 solutions 159130 answers

It is likely that what you see in manage data are cookies from a regular session. You can only clear data from the regular session that is stored in the profile folder when you are not in private browsing mode. If you start Firefox normally then you should be able to clear this data. Keep until won't have effect when you are in permanent Private Browsing mode (Always use Private Browsing mode; Never Remember History) because all data is kept in memory and purged automatically when all PB mode windows are closed. Only cookie exceptions apply to regular mode and private browsing mode.

It is likely that what you see in manage data are cookies from a regular session. You can only clear data from the regular session that is stored in the profile folder when you are not in private browsing mode. If you start Firefox normally then you should be able to clear this data. Keep until won't have effect when you are in permanent Private Browsing mode (Always use Private Browsing mode; Never Remember History) because all data is kept in memory and purged automatically when all PB mode windows are closed. Only cookie exceptions apply to regular mode and private browsing mode.
yessongs1 1 solutions 6 answers

Helpful Reply

Thanks to the Wesley Branton and Core-el. I've been wondering about the mechanics behind the site data and cache and this cleared any questions or reservations I had. Great responses !

Thanks to the Wesley Branton and Core-el. I've been wondering about the mechanics behind the site data and cache and this cleared any questions or reservations I had. Great responses !
logidip 0 solutions 1 answers

So what's the answer? This will not affect privacy in any way?

So what's the answer? This will not affect privacy in any way?
jscher2000
  • Top 10 Contributor
8801 solutions 71984 answers

Hi logidip, are you using automatic private browsing mode? In that case, cookies from your previous session are not written to disk and are dumped from memory when you Exit/Quit Firefox. If you're not sure about your setup, please start a new question with your system details:

https://support.mozilla.org/questions/new/desktop/privacy-and-security

Keep scrolling down on the pages to continue with the form.

Hi logidip, are you using automatic private browsing mode? In that case, cookies from your previous session are not written to disk and are dumped from memory when you Exit/Quit Firefox. If you're not sure about your setup, please start a new question with your system details: https://support.mozilla.org/questions/new/desktop/privacy-and-security Keep scrolling down on the pages to continue with the form.