A broken link is a hyperlink that points to a URL that no longer exists, returns an error, or cannot be reached, leaving the visitor who clicks it with an error page rather than the intended destination. When a user follows a broken link they typically encounter a 404 Not Found error, the server confirms the request was received but has no content at the requested URL. Broken links are also called dead links or link rot, the gradual decay of the web’s link graph as pages move, are deleted, or are reorganised without corresponding updates to links pointing to them.

Broken links occur everywhere on the web, within websites as broken internal links, between websites as broken external links, and in external sites linking back to pages that have been moved or deleted. The scale of link rot across the web is enormous, studies have estimated that a significant percentage of links on the web are broken at any given time, a reflection of the web’s continuous evolution as content is created, reorganised, and removed while the links pointing to the old locations persist unchanged.

For redirect management broken links represent one of the most important problems to solve. A redirect rule that sends visitors from a broken link’s old URL to the correct new URL transforms a dead end into a functioning path, recovering both the user experience and the SEO equity from backlinks that would otherwise be wasted on error responses. Understanding broken links, what causes them, how to find them, and how to fix them, is foundational to effective redirect management and site maintenance.

What causes broken links

Broken links are created whenever the relationship between a link’s URL and the content it was intended to point to is disrupted. Several distinct causes create this disruption.

Page deletion: content is removed from a website without configuring a redirect from the deleted URL to relevant remaining content. A product that is discontinued, an article that is taken down, a service page for an offering that has been retired, any deletion without a redirect creates a broken link for every external and internal link pointing to the deleted URL.

URL changes without redirects: a page’s URL changes, through CMS migration, URL structure reorganisation, or manual slug updates, but no redirect is configured from the old URL to the new. The old URL now returns a 404. All external backlinks pointing to the old URL are broken. All internal links using the old URL are broken. The content still exists at the new URL but it is inaccessible through the old address.

Domain migration without complete redirects: when a website moves from one domain to another without configuring redirects for all URLs every page that was not explicitly redirected becomes a broken link. Even comprehensive migration redirect configurations may miss some URLs, particularly deep pages, old content, or URLs discovered only through server logs rather than through active sitemaps.

Domain expiry: a domain whose registration lapses becomes unreachable, all links pointing to any URL on that domain are broken. The DNS for the domain stops resolving and all connections time out or return errors. Domain expiry is particularly damaging for domains that accumulated valuable backlinks during their active period, all of that link juice is immediately lost when the domain expires.

Server configuration changes: server configuration changes that modify URL routing, migrating from one CMS to another that uses different URL structures, changing URL rewriting rules, modifying directory structures, can break many URLs simultaneously if not carefully managed with corresponding redirect configurations.

Third-party content removal: external sites that previously hosted content at linked URLs remove or reorganise that content. A resource linked to from many pages on an external site that moves its URL creates broken outbound links across all those pages. These broken outbound links cannot be fixed by redirect management on the receiving site, they require action by the site containing the broken link.

Typos in URLs: manually entered URLs in content, navigation menus, or configuration files may contain typos that were never caught. The linked URL was never valid, the page never existed at that address. Typo-broken links are typically discovered through broken link auditing rather than through 404 monitoring since they often generate low error volumes from the beginning.

Temporary server issues becoming permanent: a server that returns 500 errors temporarily during an outage recovers when the outage ends. But if a server goes offline permanently, the hosting account is cancelled, the server is decommissioned, what appeared to be a temporary server issue becomes a permanent broken link situation.

Types of broken links

Broken links are categorised by their location, where the broken link exists and what relationship it has to the site experiencing broken link problems.

Broken internal links: links from one page on a site to another page on the same site that return errors. Internal links are entirely under the site owner’s control, both the page containing the link and the linked destination. Broken internal links indicate maintenance failures, URL changes without internal link updates, deleted pages without redirects, or typos in manually entered internal links.

Broken internal links have direct SEO consequences, they prevent link juice from flowing through the internal link structure to the linked page. They also disrupt crawl budget: Googlebot follows internal links to discover and crawl pages, and broken internal links lead Googlebot to error responses rather than content. And they damage user experience, visitors navigating internally encounter dead ends rather than the content they were seeking.

Broken outbound links: links from a site to external pages that return errors. The external page has moved, been deleted, or the external domain has expired. Outbound broken links are partially outside the site owner’s control, the external site made changes that broke the link. However the site owner controls whether the broken link is discovered and fixed, updating the link to point to the current correct external URL, removing the link, or replacing it with a link to an alternative resource.

Broken outbound links signal poor site maintenance to search engines and users. A site with many broken outbound links appears outdated and poorly maintained, a negative quality signal. Regularly auditing and fixing outbound broken links maintains site quality.

Broken backlinks, inbound links: links from external sites pointing to pages on the current site that return errors. The current site’s pages moved or were deleted without configuring redirects. These backlinks exist on external sites, they cannot be directly fixed by the site owner. But redirect management addresses them, configuring 301 redirects from the broken URL to the most relevant current page recovers the link juice from the backlink and fixes the user experience for visitors following those links.

Broken backlinks are particularly important to identify and fix because they represent wasted SEO equity: the external site’s link is passing no juice because the linked URL returns an error rather than redirecting to a live page. Recovering broken backlinks through redirect configuration is one of the highest-ROI redirect management activities.

How broken links affect SEO

Broken links affect SEO through several mechanisms, wasted link equity, crawl budget inefficiency, and quality signals.

Lost backlink equity: every external backlink pointing to a broken URL on a site is wasting its link juice. The backlink exists, the linking site made a genuine editorial decision to link to the content, but the equity from that link is lost because the linked URL returns an error rather than passing juice to a live page. Configuring 301 redirects from broken URLs to relevant live pages immediately recovers this wasted equity, turning broken backlinks into functioning equity sources.

Crawl budget waste: Googlebot follows links to discover and crawl content. When it follows links, internal or from external sites, that lead to 404 errors it has spent crawl budget on a request that produced no usable result. High volumes of broken links waste crawl budget on unsuccessful requests, budget that could have been spent crawling valuable content. Fixing broken links with redirects converts wasted crawl requests into productive ones.

Quality signals: a site with many broken internal links signals poor technical maintenance to search engines. Regular broken link auditing and fixing demonstrates ongoing technical quality, maintaining the site in a state that serves users well and enables efficient crawling. The quality signal from well-maintained links is particularly relevant for sites in competitive niches where every ranking signal matters.

User experience and engagement signals: users who click broken links and land on error pages immediately leave, contributing to negative engagement signals. High exit rates from error pages, reduced time-on-site, and abandoned user journeys are all negative engagement signals that can indirectly affect rankings. Well-maintained links that deliver users to intended destinations support positive engagement.

Fixing broken links with redirects

Redirect management is the primary tool for fixing broken links, particularly broken backlinks from external sites that cannot be directly edited by the site owner.

301 permanent redirects for broken URLs: the most effective fix for a broken URL that has backlinks. Configuring a 301 redirect from the broken URL to the most relevant live page transforms the broken backlink into a functioning equity source. The external site’s link continues to point to the old URL, the site owner cannot change that, but the redirect ensures that visitors following the link arrive at relevant content and that link juice flows to the redirect destination.

The redirect destination should be the most topically relevant live page, not simply the homepage. A backlink to /products/discontinued-item is better served by a redirect to /products/similar-item than to the homepage, the more relevant the destination the more equity is preserved and the better the user experience.

Prioritising redirects by backlink value: when many broken URLs need redirects prioritise based on backlink value. URLs with many high-quality backlinks, checked through Ahrefs, Moz, or similar tools, represent the most equity currently being wasted. Fixing these first recovers the most equity per redirect configured.

Bulk redirect configuration for site migrations: when a site migration creates many broken URLs simultaneously bulk redirect configuration allows all redirects to be deployed at once rather than one at a time. A redirect map, a spreadsheet mapping old URLs to new URLs, can be imported into a redirect management platform to create hundreds or thousands of redirect rules simultaneously.

Fallback redirects for unmapped URLs: not every broken URL can be individually mapped to a specific destination. A fallback redirect: a global rule sending all unmatched URLs to a relevant page or the homepage, ensures that no visitor who follows a broken link ends up on an error page. While a fallback to the homepage is less precise than a specific mapping it is better than returning a 404 error.

Finding broken links

Identifying broken links requires systematic auditing, both internal links and broken backlinks from external sites.

Crawl-based internal link auditing: crawling tools, Screaming Frog, Sitebulb, Ahrefs Site Audit, Semrush Site Audit, crawl a site following all internal links and identifying those that return error responses. The output is a list of broken internal links with the linking page, the broken URL, and the error response code. This provides a complete inventory of internal broken links for a site.

Running a full site crawl periodically, monthly for active sites, quarterly for more stable sites, maintains an ongoing inventory of internal broken links and tracks whether previously fixed links have broken again.

Google Search Console coverage reports: the Coverage report in Google Search Console shows URLs that returned 404 or other errors when Googlebot crawled them. This reflects Googlebot’s actual crawl experience, broken links that Googlebot followed and found broken. The report includes the linking pages that led Googlebot to the broken URLs, providing context for fixing the broken links at the source as well as configuring redirects.

Backlink tool broken link reports: Ahrefs, Moz, and Semrush provide broken backlink reports, identifying external backlinks pointing to URLs on the current site that return errors. These reports show which external sites are linking to broken URLs, the anchor text of the broken backlinks, the domain authority of the linking sites, and the specific broken URLs. This is the primary tool for identifying broken backlinks that are wasting link juice.

Server log analysis: analysing web server logs for 404 responses identifies every URL that is returning broken link errors, including URLs not discovered through crawling or backlink tools. Server logs capture the complete record of actual visitor and crawler requests, providing the most comprehensive broken link inventory but requiring more technical effort to analyse.

User-reported broken links: users who encounter broken links sometimes report them, through contact forms, social media mentions, or direct email. User reports are not a systematic discovery method but they identify broken links that are actively affecting real visitors, worth prioritising for quick fixes.

Preventing broken links

Preventing broken links from being created is more efficient than continuously finding and fixing them after the fact.

Redirect-first URL changes: establishing a workflow where configuring a redirect is a required step before any URL change or page deletion. The redirect must be in place before the URL change is made, ensuring no gap during which the old URL returns a 404 before the redirect is configured.

Internal link auditing after site changes: whenever URL structures change or pages are deleted run an immediate internal link audit to identify broken internal links created by the change. Fix broken internal links by updating them to point directly to the new canonical URL rather than relying on redirects for internal navigation.

Monitoring for new 404 errors: setting up automated monitoring for new 404 errors, through Google Search Console email alerts, server log monitoring, or uptime monitoring tools, catches new broken links quickly after they are created. Rapid detection allows quick fixes before significant equity loss or user experience damage accumulates.

Canonical tag maintenance: keeping canonical tags updated when URLs change prevents situations where canonical tags point to broken URLs. A broken canonical URL wastes the canonicalisation signal, search engines cannot consolidate equity to a URL that returns an error.