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

nytimes detecting Private Mode

  • 4 cavab
  • 2 have this problem
  • 3 views
  • Last reply by Jeenu

more options

I updated to Firefox 66 on Linux yesterday. I don't know if it's the browser version, but I noticed that nytimes.com started picking up that I'm browsing the site in private mode.

Interestingly, this is something that used to happen on my Chrome book when I used private mode, but this on Firefox, this is a first for me. It may well be that nytimes changed their code to do this, but I wonder upgrade to FF 66 contributed to this.

In any case, I wonder how a site can pick up if the user is browsing in private mode.

I updated to Firefox 66 on Linux yesterday. I don't know if it's the browser version, but I noticed that nytimes.com started picking up that I'm browsing the site in private mode. Interestingly, this is something that used to happen on my Chrome book when I used private mode, but this on Firefox, this is a first for me. It may well be that nytimes changed their code to do this, but I wonder upgrade to FF 66 contributed to this. In any case, I wonder how a site can pick up if the user is browsing in private mode.

All Replies (4)

more options

PB if detected by the site might now let you access since they sometimes require tracking or cookies to work.

Modified by WestEnd

more options

In private windows, Firefox disables saving data to disk using IndexedDB, so that is one possible characteristic sites might use.

more options
more options

Thanks.

A 7-years-old bug!