4 ms·

How does it do that? Do browsers set a flag? That seems like a privacy hole.

bentruyman 9y ago
There are certain browser APIs disabled in the browser in incognito mode that can be detected. How else would you implement incognito mode?
- Analemma_ 9y ago
  That's interesting. Why are the storage APIs disabled, instead of just using ephemeral storage that goes away when the window is cleared?
  - lallysingh 9y ago
    It's less work to disable them. There's likely already an API access control system in place, for internal-only APIs, testing, etc.
    - eridius 9y ago
      It also means sites can avoid promising to do things that aren't actually possible, like saving information for access next time.
- brohee 9y ago
  By sandboxing, e.g. localStorage fully functional but deleted at the end of the session...
  - 2fifty3 9y ago
    Mozilla recently released containerized tabs[0], I imagine the next logic step is building containerized Private Browsing Mode [0]: https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/ https://addons.mozilla.org/en-US/firefox/addon/multi-account...
    - Paul-ish 9y ago
      My understanding is that things actually went the other way. Private browsing came first, then the same approach was used to create more labels than just "private" and not "private". I think more features may be turned off in private browsing mode though.
    - m-p-3 9y ago
      I use multiple computers daily and not having those synced with my Firefox account is a pain in the ass.
- deleted 9y ago
  [deleted]
Jacqued 9y ago
My guess is that they feature detect, using disabled stuff (eg localStorage error 22 on safari private mode) to find out if your browser looks like one in private mode.
makepanic 9y ago
Peeking into the source: /** * Detects incognito/private mode in various browsers. * * Adapted from: * https://gist.github.com/cou929/7973956 */
- Something1234 9y ago
  Link for the lazy. https://gist.github.com/cou929/7973956 https://gist.github.com/cou929/7973956

There are certain browser APIs disabled in the browser in incognito mode that can be detected. How else would you implement incognito mode?

Analemma_ 9y ago
That's interesting. Why are the storage APIs disabled, instead of just using ephemeral storage that goes away when the window is cleared?
- lallysingh 9y ago
  It's less work to disable them. There's likely already an API access control system in place, for internal-only APIs, testing, etc.
  - eridius 9y ago
    It also means sites can avoid promising to do things that aren't actually possible, like saving information for access next time.
brohee 9y ago
By sandboxing, e.g. localStorage fully functional but deleted at the end of the session...
- 2fifty3 9y ago
  Mozilla recently released containerized tabs[0], I imagine the next logic step is building containerized Private Browsing Mode [0]: https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/ https://addons.mozilla.org/en-US/firefox/addon/multi-account...
  - Paul-ish 9y ago
    My understanding is that things actually went the other way. Private browsing came first, then the same approach was used to create more labels than just "private" and not "private". I think more features may be turned off in private browsing mode though.
  - m-p-3 9y ago
    I use multiple computers daily and not having those synced with my Firefox account is a pain in the ass.
deleted 9y ago
[deleted]

Jacqued 9y ago

My guess is that they feature detect, using disabled stuff (eg localStorage error 22 on safari private mode) to find out if your browser looks like one in private mode.

makepanic 9y ago

Peeking into the source: /** * Detects incognito/private mode in various browsers. * * Adapted from: * https://gist.github.com/cou929/7973956 */

Something1234 9y ago
Link for the lazy. https://gist.github.com/cou929/7973956 https://gist.github.com/cou929/7973956