Link rot

Link rot is the gradual process by which links that used to work stop working. The page they point to gets deleted, moved without a redirect, or the site it lived on shuts down entirely. The defining feature is that nothing changes on your side: your page is untouched, your server reports no error, and your analytics look normal, because the failure happens on somebody else's machine. That is why link rot is usually discovered by a reader rather than by the person who published the link.

This is measurable, and the numbers are larger than most people guess. The Pew Research Center sampled pages from the Common Crawl archive for every year from 2013 to 2023 and then tried to load them again. A quarter of all the pages sampled across that decade were no longer reachable as of October 2023. Broken down by age, 38% of the pages that existed in 2013 were gone, against 8% of the pages that were only a year old. The same study found that 23% of news pages and 21% of government pages already contain at least one broken link, and that 54% of Wikipedia articles have at least one dead link in their references.

Broken outbound links do not carry a direct ranking penalty, and anyone who tells you otherwise is selling something. The damage is real but indirect, and it arrives by three routes. Crawl budget gets spent requesting pages that return errors instead of pages you want indexed, which matters most on large sites. Internal links that point at renamed slugs stop passing authority between your own pages, so the structure you built to support an important page quietly stops supporting it. And readers who click a dead link go back to the search results to find what they wanted, which is precisely the signal search engines are designed to read. A page full of dead ends also simply looks abandoned, which affects whether anyone cites or links to it again.

On a monetised site the cost stops being reputational and becomes arithmetic. A dead affiliate link earns nothing from traffic you are still paying to acquire or still earning organically, and the post keeps ranking and keeps sending people to it. Worse is the case that does not look broken at all: a link that still loads a working product page but arrives without your tracking tag, because a redirect along the chain dropped it or the product was relisted by another seller. The reader buys, the merchant ships, and the commission is credited to nobody. Since the page returns a healthy 200 status, no ordinary broken link checker will ever mention it, and your revenue simply drifts down without an explanation.