This study applies the Spiral of Silence framework to explore how online opinion climates affect individuals' willingness to post in forums. Through a 2 × 2 experiment, manipulating website source (mainstream news vs. ideologically homogeneous activist group) and opinion congruency (minority vs. majority), it was found that willingness to post was primarily influenced by how closely an individual’s opinion aligned with the prevailing opinions in the forums. The study also identified factors that deter individuals from posting.