Looking for logging into the Salesforce Trailhead site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Salesforce Trailhead site. After that you can login as usual with your login credentials.
https://trailhead.salesforce.com/ja
https://developer.salesforce.com/forums/%3Fid%3D906F00000005GAVIA2
https://help.salesforce.com/apex/HTViewSolution%3Fid%3D000249165%26language%3Dja
https://login.salesforce.com/
https://tyoshikawa1106.hatenablog.com/entry/2016/09/19/230617
https://tyoshikawa1106.hatenablog.com/entry/2015/11/13/223547
http://certification.force.com/adminlearnerpak/servlet/servlet.FileDownload%3Ffile%3D0154A00001u4Wl0
https://qiita.com/haruto167/items/8afb35590a8622d7e218
https://force.desk.com/customer/en/portal/articles/2643793-trailhead-profile-signup-login-faq%3Fb_id%3D13478
https://salesforce.stackexchange.com/questions/219282/my-salesforce-training-account-has-expired-now-i-can-not-login-to-trailhead-can
https://whartonexeced.zendesk.com/hc/en-us/articles/360000132666-Salesforce-s-Trailhead-Login-and-Profile-Setup
https://twitter.com/trailhead
https://fionta.com/news/creating-a-salesforce-account/