Broken link building is a targeted off-page SEO tactic where you find backlinks pointing to non-functioning pages on other websites and offer your relevant content as a replacement. Start by using tools like Semrush's Backlinks tool to identify broken pages on competitor sites or within your niche. Filter for 'Broken Pages' and examine the backlinks leading to these dead URLs. Reach out to the webmasters or content creators linking to these broken pages and suggest your active, relevant resource as a replacement link. This method not only helps webmasters fix their broken links but also earns you valuable backlinks from authoritative domains, enhancing your site’s trustworthiness and authority in the eyes of search engines. [Semrush]