I’ve been exploring SharePoint 2013 in recent days and noticed that the ‘Sign in as Different User’ option or action from the welcome control (user menu) seems to have been removed or forgotten from the user interface in this build.
For someone who works with SharePoint as I do, any kind of administration, developing or testing that requires you to sign in as another you will now become convoluted from the previous version and is somewhat frustrating and annoying. Others such as Nick Grattan have discussed this issue and possible workarounds.
Of all the workarounds currently available such as browsing to the closeConnection page directly, modifying the welcome control and adding the control back (I do not recommend this approach), creating a javascript bookmark, embedding jQuery into the master page to insert the option back in the menu and lastly launching the browser with the RunAs option my preference will remain to browse directly to the closeConnection page:
/_layouts/closeConnection.aspx?loginasanotheruser=true
Or alternatively, use the javascript bookmark Cory Peters has kindly created:
javascript:window.location.href=”http://”+window.location.host+”/_layouts/closeConnection.aspx?loginasanotheruser=true”;
It will be interesting to see what others do and as to whether or not the option gets added back by Microsoft in a future update.