The link checker code in this post is also available in this GitHub Gist. Puffins in the rain, Iceland. Photo by Yves Alarie. Previously on link checking… We discussed the link rot issue before. We also built a simple link checker for blogdown projects based on the XML sitemap generated by Hugo. In reality, I maintain many more bookdown projects and Quarto projects than blogdown projects. Searching site: bookdown::bookdown_sitealso shows that there are 10,000+ bookdown projects hosted on GitHub …