Private browsing. Incognito. Privacy mode.
Web browser functions like those trace their roots back more than a decade, and the feature - first found in a top browser in 2005 - spread quickly as one copied another, made tweaks and minor improvements.
But privacy-promising labels can be treacherous. Simply put, going "incognito" is as effective in guarding online privacy as witchcraft is in warding off a common cold.
That's because private browsing is intended to wipe local traces of where you've been, what you've searched for, the contents of forms you've filled. It's meant to hide, and not always conclusively at that, your tracks from others with access to the personal computer.
At their most basic, these features promise that they won't record visited sites to the browsing history, save cookies that show you've been to and logged into sites, or remember credentials like passwords used during sessions.
Your traipses through the web are still traceable by Internet providers - and the authorities who serve subpoenas to those entities - employers who control the office network and advertisers who follow your every footstep. So much for privacy, eh?
Knowing the limitations of incognito doesn't make the tool worthless. There are reasons, even good reasons, for masking what you do on a shared PC or Mac. Just don't credit the terminology with more power than it represents.
On the practical side, we've assembled instructions and insights to the incognito features offered by the top four browsers: Google Chrome, Mozilla's Firefox, Apple's Safari and the soon-to-perish-and-rise-again Edge, from Microsoft.
How to go incognito in Google Chrome
Although incognito has become a label for any browser's private mode, that's what Google named the feature when it debuted in late 2008, just months after the search giant launched its browser.
The easiest way to open an Incognito window is with the keyboard shortcut combination Ctrl-Shift-N (Windows) or Command-Shift-N (macOS).
Another way is to click on the menu on the upper right - it's three vertical dots - and select New Incognito Window from the list.
The new Incognito window can be recognized by the dark background and the stylized "spy" icon just to the left of the three-dots menu. Chrome also reminds users of just what Incognito does and doesn't do each time a new window is opened. The message may get tiresome for regular Incognito users, but it may also save a job or reputation; it's important that users remember that Incognito doesn't prevent ISPs, businesses, schools and organizations from knowing where customers, workers, students and others went on the web or what they searched for.
Once a tab has been filled with a site, Chrome continues to remind users that they're in Incognito by the dark background of the address bar and window title.
A link on an existing page can be opened directly into Incognito by right-clicking the link, then choosing Open Link in Incognito Window from the resulting menu.
To close an Incognito window, shutter it like any other Chrome window by clicking the X in the upper right corner (Windows) or the red dot in the upper left (macOS).
Pro tip: Chrome's Incognito runs with all extensions automatically disabled. To allow one or more add-ons to run within Incognito, steer to the Extensions page - in Windows, it's under More tools - click the Details box and look for the slider alongside the text Allow in incognito. Move the slider to the right to enable the extension in Incognito.
How to do private browsing in Mozilla Firefox
After Chrome trumpeted Incognito, browsers without something similar hustled to catch up. Mozilla added its take - dubbed Private Browsing - about six months after Google, in June 2009, with Firefox 3.5. (This was before Firefox started iterating every six weeks, when the numeric changes were much less frequent.)
From the keyboard, a private browsing session can be called up using the combination Ctrl-Shift-P (Windows) or Command-Shift-P (macOS).
Alternately, a private window will open from the menu at the upper right of Firefox - three short horizontal lines - after selecting New Private Window.
A private session window is marked by the purple "mask" icon at the right of the title bar of the Firefox frame. In Windows, the icon is to the left of the minimize/maximize/close buttons; on a Mac, the mask squats at the far right of the title bar.
Like other browsers, Firefox warns users that private browsing is no cure all for privacy ills but is limited in what it blocks from being saved during a session. "Private Browsing doesn't make you anonymous on the Internet," the caution reads. "Your employer or Internet service provider can still know what page you visit."
Notable in Firefox's version of incognito is that what Mozilla calls Content Blocking remains enabled during a private session. That should not be a surprise, as the forerunner, labeled Tracking Protection, was introduced as a default to Private Windows long before being added to Firefox's standard mode. (In fact, Content Blocking remains off in Firefox standard until the user manually enables it in Options (Windows) or Preferences (macOS).)
A link can be opened into a Firefox Private Window by right-clicking the link, then choosing Open Link in New Private Window from the menu.
To close a Private Window, shut it down just as any Firefox window by clicking the X in the upper right corner (Windows) or the red dot in the upper left (macOS).
Pro tip: Firefox can be set to always open in private windows. Here's how: From the menu, choose Options (Windows) or Preferences (macOS), select Privacy & Security from the choices on the left, scroll down to History and pick Never remember history from the drop-down. Restart Firefox.
"This is equivalent to always being in Private Browsing mode," Mozilla said in a support document. However, when Never remember history has been enabled, the purple mask reminder does not appear in the title bar of the browser.
How to browse in peace with Apple's Safari
Chrome may get more attention for its Incognito mode than any other browser, but Apple's Safari was actually the first to adopt the idea of private browsing. The term private browsing was first bandied in 2005 to describe Safari 2.0 features that limited what was saved by the browser. (Safari 2.0 was packaged with Mac OS X 10.4, aka "Tiger," which released in April 2005.)
Side note: Early in private browsing, the label porn mode was often used as a synonym to describe what many writers and reporters assumed was the primary application of the feature. The term has fallen out of general use.
To open what Safari calls a Private Window on a Mac, users can do a three-key combination of Command-Shift-N, the same shortcut Chrome adopted.
Otherwise, a window can be called up by selecting the File menu and clicking on New Private Window.
Safari tags each Private Window by darkening the address bar. It also issues a reminder of what it does - or more accurately - what it doesn't do. "Safari will keep your browsing history private for all tabs of this window. After you close this window, Safari won't remember the pages you visited, your search history or your AutoFill information," the top of the page note reads. The warning is more terse than those of other browsers and omits cautions about still-visible online activity.
Unlike Firefox, which automatically turns on additional blocking in its incognito mode, Safari does not enable the browser's Intelligent Tracking Protection (ITP), which was upgraded last year to ITP 2 with Safari 12 and macOS Mojave. To block cross-site trackers - the kind advertisers use to follow an individual as they browse from site to site - Safari users must switch on cross-site tracking themselves. It will then work in both Safari's standard and private modes.
To switch on cross-site tracking, choose Preferences from the Safari menu, click the Privacy icon in the row of icons at the top of the window, check the box marked Prevent cross-site tracking and then close the Preferences window.
A link cannot be opened from a page directly into a Private Window in Safari. Instead, users must first open the site with that link in a Private Window, then right-click the link and select Open Link in New Private Tab or Open Link in New Private Window. This is a more cumbersome process than in browsers like Chrome and Firefox.
Close a Private Window just as any Safari window, by clicking the red dot in the upper left corner of the browser frame.
Pro tip: Once in a Safari Private Window, opening a new tab - either by clicking the + icon at the upper right or by using the Command-T key combo - omits the Private Browsing Enabled notice. Other browsers, such as Firefox, repeat their cautionary messages each time a tab is opened in an incognito session.
How to privately browse in Microsoft Edge (for now)
Edge, the default browser for Windows 10, borrowed the name of its private browsing mode - InPrivate - from Internet Explorer (IE), the now-obsolete-but-still-maintained legacy browser. InPrivate appeared in IE in March 2009, about three months after Chrome's Incognito and three months before Firefox's privacy mode. When Edge was released in final form, as part of Windows 10's late-July 2015 launch, InPrivate was part of the package.
At the keyboard, the combination of Ctrl-Shift-P opens an InPrivate window.
A slower way to get there is to click on the menu at the upper right - it's three dots arranged horizontally - and choose New InPrivate window from the menu.
Edge marks its InPrivate Windows more unobtrusively than any other browser: The blue-colored rectangle at the upper left with InPrivate in white text is the only indicator. Nor does Edge remind users of InPrivate's particulars or warn them that anonymity is not its purpose; Microsoft's browser is the only one of the top four that doesn't bother with such information.
It's also possible to launch an InPrivate session by right-clicking a link within Edge and selecting Open in new InPrivate window. Doing that when an InPrivate window is already open does not add that as a tab to the private browsing session, but opens an entirely new InPrivate frame.
To end InPrivate browsing, simply shut the window by clicking the X in the upper right corner.