Microblogs have become an increasingly important source of information, both in the U.S. (Twitter) and in China (Weibo). However, the brevity of microblog updates, combined with increasing access of microblog content through search rather than through direct network connections, makes it challenging to assess the credibility of news relayed in this manner. This paper reports on experimental and survey data that compare the impact of several features of microblog updates (author’s gender, name style, profile image, location, and degree of network overlap with the reader) on credibility perceptions among U.S. and Chinese audiences. We reveal the complex mechanism of credibility perceptions, identify several key differences in how users from each country critically consume microblog content, and discuss how to incorporate these findings into the design of improved user interfaces for accessing microblogs in different cultural settings.