Tumblr users aren't required to set up their accounts with their real names. Users can also change the names of their blogs and blog URLs at any time. As a result, Tumblr provides two methods to find people on the site. Search for someone using the site's internal search engine or its contacts lookup tool.
When you type a username or blog name in the Search Tumblr field, two categories of results appear. The Search category offers one or more links to pages that display examples of blogs that contain the name and instances of the name in posts or tags. The Blogs category offers one or more links to blogs that contain the name anywhere in their titles or URLs.
Tumblr also helps you find friends, family and colleagues who use the site by cross-referencing email addresses from Facebook and Gmail contacts against addresses used to set up Tumblr accounts. On your Dashboard, click "Find Blogs," select "People You Know," select "Facebook" or "Gmail" and then authorize access to your contacts when prompted.
Search results can include non-relevant links because of commonly used names. To narrow the results, always place quotation marks around a username or blog name in the search box. Some people disable the "Allow search engine to index your blog" option. You won't be able to find those blogs using Tumblr's search box or any external search engines.