Internal linking is the practice of placing hyperlinks within a website that point from one page on that domain to another page on the same domain, allowing both users and search engine crawlers to navigate the site's content.
Unlike external links, which point to pages on other websites, internal links are entirely within a site owner's control. This makes them one of the most actionable tools in SEO, because they directly influence how authority is distributed across a site and how efficiently search engines discover and index its pages.
How Internal Links Distribute Authority
Search engines assign a measure of authority, sometimes called PageRank or link equity, to each page based on the quantity and quality of links pointing to it. When a high-authority page links to another page on the same site, it passes a portion of that authority along. A well-structured internal linking strategy ensures that important pages, such as product pages or cornerstone articles, receive a stronger share of this authority rather than it being spread thinly or concentrated on less significant pages.
This is closely related to the concept of a topic cluster, a site architecture model in which a central "pillar" page covering a broad subject links out to more specific "cluster" pages, and those cluster pages link back to the pillar. This bidirectional linking pattern reinforces the topical relevance of the entire group in the eyes of search engines.
Internal Links and Crawl Efficiency
Search engine crawlers discover pages by following links. A page that has no internal links pointing to it, sometimes called an orphan page, is difficult for crawlers to find and may never be indexed. Thoughtful internal linking ensures that every important page is reachable within a reasonable number of clicks from the homepage, which is especially significant for large sites operating under a limited crawl budget, the number of pages a search engine is willing to crawl within a given period.
The Role of Anchor Text
The clickable text of an internal link, known as anchor text, carries meaningful signals to search engines about the content of the destination page. Using descriptive, keyword-relevant anchor text helps search engines understand what a linked page is about, reinforcing its relevance for specific queries. Generic anchor text such as "click here" or "read more" provides no such signal and represents a missed opportunity.
Practical Considerations
Effective internal linking requires a deliberate approach rather than adding links arbitrarily. Links should be contextually relevant, appearing within the body of content where they naturally add value for the reader. The number of links on any given page should remain reasonable, as an excessive number can dilute the authority passed to each destination and create a poor user experience. Auditing internal links periodically, particularly after site restructures or content migrations, helps prevent broken links and ensures the linking architecture continues to serve both users and search engines accurately.