\n\n(We just forced every registered account in the entire network to log off and log back in to ensure that everyone has logged in under this new regime -- so everyone should meet criteria #1 by definition.)\n\nGlobal logins are tricky for us because we need \u003Cstrong>cross-domain identity\u003C/strong>. That is, each of the following sites should, somehow, just magically \u003Cem>know\u003C/em> who you are:\n\u003Cul>\n \t\u003Cli>stackoverflow.com\u003C/li>\n \t\u003Cli>serverfault.com\u003C/li>\n \t\u003Cli>superuser.com\u003C/li>\n \t\u003Cli>stackexchange.com\u003C/li>\n\u003C/ul>\n(not to mention that \u003Cem>all\u003C/em> current \u003Ca href=\"http://stackexchange.com/sites\">Stack Exchange 2.0 sites\u003C/a> will eventually have custom domain names of their own choosing.)\n\nWhile subdomains such as \u003Ccode>chat.serverfault\u003C/code> and \u003Ccode>meta.serverfault\u003C/code> are easy if you store your cookies the right way, getting access to cookies at different domains is, to put it charitably, \u003Cem>a friggin' nightmare\u003C/em>. The whole third party cookie story -- that is, reading or writing cookies stored at a domain \u003Cem>other\u003C/em> than the one you're currently on -- is irreversibly screwed up, and getting worse with every new browser release, thanks mostly to unscrupulous ad networks.\n\nSo, we gave up on using third-party cookies. Instead, we use \u003Ca href=\"http://diveintohtml5.org/storage.html\">HTML 5 Local Storage\u003C/a> for global authentication, at our centralized domain \u003Ca href=\"http://stackauth.com\">stackauth.com\u003C/a>. Now, this does require a modern browser, though not unreasonably so: IE8+, Chrome, Safari, FireFox 3.6+, and Opera 10.61+ are all supported.\n\nKevin has labored mightily to get all this working, and we've been silently running beta revisions of global auth across the network for the last two or three weeks as we work out the kinks and test. We now think it's (mostly) ready for prime time.\n\nAs with all things technically complex, there are some caveats. Global auth should work fine in the typical case -- and even if global auth is completely down, it can \u003Cem>never\u003C/em> prevent you from logging into a site the traditional way. But please be advised that we may not be able to automatically log in you in, if ...\n\u003Cul>\n \t\u003Cli>You've been to the target site recently \u003Cem>without\u003C/em> a global auth session (click the \"login\" link at the top of every page to force it)\u003C/li>\n \t\u003Cli>You're using some sort of anonymizer that interferes with \u003Ca href=\"http://en.wikipedia.org/wiki/HTTP_referrer\">HTTP Referrer\u003C/a>\u003C/li>\n \t\u003Cli>You aren't using the same OpenId across all sites\u003C/li>\n \t\u003Cli>You're visiting a \u003Ca href=\"http://blog.stackoverflow.com/2010/07/new-per-site-metas/\">per-site meta\u003C/a> without first logging into the parent (child metas don't use global auth; they rely on identity coming from the parent site.)\u003C/li>\n\u003C/ul>\n(And if you're looking for excruciating technical detail on how this all works, Kevin has \u003Ca href=\"http://meta.stackoverflow.com/questions/64260/how-does-sos-new-auto-login-feature-work/64274#64274\">documented that here on meta\u003C/a>.)\n\nIf you have issues with global auth and need to troubleshoot, I suggest starting by \u003Cstrong>forcing a global logout\u003C/strong> -- you can do this by clicking \"log out\", then clicking the big \"log out everywhere\" button.\n\n\u003Cimg src=\"http://stackoverflow.blog/wp-content/uploads/2017/02/log-out-everywhere-button.png\" alt=\"\" />\n\nBear in mind that you must hold accounts on the sites -- global authentication will not automatically create accounts for you (with the lone exception of \u003Ca href=\"http://stackexchange.com\">http://stackexchange.com\u003C/a> itself). That said, as long as you're logged into one account in our network, you should now be automatically logged into \u003Cem>all\u003C/em> your accounts.\n\nDo you love network security? If so, there is plenty of work to be found. Check out the latest opportunities in our \u003Ca href=\"https://stackoverflow.com/jobs/developer-jobs-using-security?utm_source=so-owned&utm_medium=blog&utm_campaign=dev-c4al&utm_content=c4al-link\" target=\"_blank\" rel=\"noopener noreferrer\">network security job listings\u003C/a>.","html","2010-09-11T12:00:00.000Z",{"current":441},"global-network-auto-login",[443,451,456,461,466,471],{"_createdAt":444,"_id":445,"_rev":446,"_type":447,"_updatedAt":444,"slug":448,"title":450},"2023-05-23T16:43:21Z","wp-tagcat-community","9HpbCsT2tq0xwozQfkc4ih","blogTag",{"current":449},"community","Community",{"_createdAt":444,"_id":452,"_rev":446,"_type":447,"_updatedAt":444,"slug":453,"title":455},"wp-tagcat-company",{"current":454},"company","Company",{"_createdAt":444,"_id":457,"_rev":446,"_type":447,"_updatedAt":444,"slug":458,"title":460},"wp-tagcat-design",{"current":459},"design","Design",{"_createdAt":444,"_id":462,"_rev":446,"_type":447,"_updatedAt":444,"slug":463,"title":465},"wp-tagcat-serverfault-com",{"current":464},"serverfault-com","Serverfault.com",{"_createdAt":444,"_id":467,"_rev":446,"_type":447,"_updatedAt":444,"slug":468,"title":470},"wp-tagcat-stackexchange",{"current":469},"stackexchange","Stackexchange",{"_createdAt":444,"_id":472,"_rev":446,"_type":447,"_updatedAt":444,"slug":473,"title":475},"wp-tagcat-superuser-com",{"current":474},"superuser-com","Superuser.com","Global Network Auto-Login",[478,484,489,494],{"_id":479,"publishedAt":480,"slug":481,"sponsored":12,"title":483},"1d082483-6dc6-424b-8b09-9c84b54779da","2025-09-02T17:00:00.000Z",{"_type":10,"current":482},"back-to-school-developers-at-stack-overflow-have-some-advice-for-you","Back to school? Developers at Stack Overflow have some advice for you",{"_id":485,"publishedAt":480,"slug":486,"sponsored":12,"title":488},"5cd91820-9515-4be5-87ae-e919fd443c18",{"_type":10,"current":487},"getting-started-on-stack-overflow-a-step-by-step-guide-for-students","Getting started on Stack Overflow: a step-by-step guide for students",{"_id":490,"publishedAt":480,"slug":491,"sponsored":12,"title":493},"614538a9-c352-4024-adf1-fa44a9f911b6",{"_type":10,"current":492},"stack-overflow-is-helping-you-learn-to-code-with-new-resources","Stack Overflow is helping you learn to code with new resources",{"_id":495,"publishedAt":480,"slug":496,"sponsored":12,"title":498},"763b1d36-83d8-4178-9c2d-32d705ea1d7b",{"_type":10,"current":497},"introducing-your-newest-study-buddy-stackoverflow-ai","Introducing your newest study buddy: stackoverflow.ai",{"count":500,"lastTimestamp":501},5,"2023-05-25T09:45:54Z",["Reactive",503],{"$sarticleModal":504},false,["Set"],["ShallowReactive",507],{"sanity-VdRR14UUjlbX70gFhKYMYuyYkD-BbLko1GGDHCDWa9Q":-1,"sanity-comment-wp-post-3924-1756979714458":-1},"/2010/09/11/global-network-auto-login"]