What Is an Internal Link Graph?

What an internal link graph shows

An internal link graph is a visual representation of the internal linking structure of a website. It shows how pages within a domain are connected to each other through hyperlinks. Each page is represented as a node, and each internal link from one page to another is represented as an edge (line or arrow) connecting those nodes.

This graph illustrates the flow of "link equity" or "PageRank" throughout a site, helping to identify how authority is distributed and which pages are most accessible and discoverable to search engine crawlers and users. By understanding the intricate network of internal links, site owners can optimize their site for better search engine visibility and user experience.

The four patterns to look for

When analyzing an internal link graph, several patterns emerge that indicate the health and efficiency of a website's linking structure. Recognizing these patterns helps in diagnosing potential issues and opportunities for optimization. The four primary patterns to observe are:

1. Orphan pages: Pages with no incoming internal links.
2. Over-linked pages (potential PageRank sinks): Pages that link out to an unusually high number of other pages.
3. Hub pages: Pages that have a significant number of incoming links and/or link out to a focused set of related pages, acting as central points of authority.
4. Topic clusters: Groups of semantically related pages tightly interconnected by internal links, revolving around a central pillar page.

These patterns offer insights into how effectively link equity is distributed and whether search engine crawlers can efficiently discover all valuable content on the site.

Orphan pages and why they hurt

An orphan page is a page on your website that has no internal links pointing to it from other pages on the same site. While these pages might still be accessible if they are included in an XML sitemap or have external backlinks, they are effectively isolated within your site's structure.

Orphan pages present several problems for SEO and user experience:

• Reduced crawlability: Search engine crawlers typically discover new content by following internal links. Without any links, crawlers may find it difficult or impossible to discover these pages, leading to them being unindexed or indexed very slowly.
• Wasted content: Content on orphan pages, no matter how valuable, receives little to no internal link equity. This diminishes its potential to rank in search results, effectively wasting the effort put into creating it.
• Poor user experience: Users are unlikely to spontaneously discover orphan pages through site navigation. This reduces engagement and the utility of the content.
• Security risks: In some cases, sensitive or outdated content might become an orphan and linger on the site, posing a security or content quality risk if discovered by other means.

LemRank identifies pages with 0 incoming internal links as orphans. These pages are flagged in the internal link graph visualization and detailed reports for easy identification and action. Addressing orphan pages typically involves adding relevant internal links from authoritative and related pages on your site.

Hub authority and PageRank sculpting

Hub pages are central pages within a website's internal linking structure that accumulate significant internal link equity and distribute it to other related pages. These pages often function as pillar content, category pages, or directory pages.

Characteristics of effective hub pages:

• High number of incoming internal links: Other pages on the site link to the hub, indicating its importance and relevance.
• Strategic outgoing internal links: The hub page links out to a focused set of related sub-pages or articles, passing on its accumulated authority.
• Thematic relevance: Hubs are typically comprehensive resources on a particular topic, covering broad aspects and linking to more detailed content.

PageRank sculpting is the practice of strategically distributing link equity throughout a website using internal links. By identifying hub pages and optimizing their linking patterns, you can direct authority to the most important pages on your site. For example, a high-authority blog category page that links to its top 5 evergreen articles helps those articles rank better.

Conversely, pages with an unusually high number of outgoing internal links (e.g., 100+ links) can dilute the link equity passed to each individual linked page. These "potential PageRank sinks" are flagged by LemRank. While not always problematic, an excessive number of links from a single page, especially from lower-authority pages, could indicate a less efficient distribution of PageRank. Reviewing such pages helps ensure that link equity is used effectively to boost the most valuable content.

Building topic clusters with links

Topic clusters are interconnected groups of web pages focused on a specific subject, designed to establish topical authority in the eyes of search engines. This structure typically consists of a central "pillar page" that provides a broad overview of a subject and multiple "cluster content" pages that dive deeper into specific sub-topics related to the pillar.

The internal linking strategy is crucial for building effective topic clusters:

1. Pillar page to cluster content: The pillar page links out to all relevant cluster content pages. These links signal that the cluster content provides more detailed information on aspects covered broadly by the pillar.
2. Cluster content to pillar page: Each cluster content page links back to the pillar page, reinforcing the pillar's authority on the overarching topic.
3. Cluster content to cluster content (optional but beneficial): Relevant cluster content pages can also link to each other when there is a strong thematic connection, further strengthening the topical network.

Using an internal link graph to visualize these connections helps ensure that:

• All cluster content is properly linked to the pillar.
• No pages within the cluster are orphaned or isolated.
• The overall structure logically reflects the topical hierarchy.

For example, a pillar page on "Content Marketing Strategies" might link to cluster pages like "Blogging for SEO," "Video Marketing Tips," and "Email Marketing Best Practices." Each of those cluster pages would then link back to the "Content Marketing Strategies" pillar. Analyzing the internal link graph allows you to confirm that a tight, relevant cluster has been formed.

How LemRank crawls and visualizes your graph

LemRank's internal link graph provides a dynamic and comprehensive view of your website's linking architecture. Here is how it facilitates this:

1. Site Audit Crawler: LemRank employs a dedicated site audit crawler to discover all publicly accessible pages on your domain. This crawler respects your robots.txt directives, honoring any disallowed paths or crawl delays. To avoid overwhelming your server, the crawler adheres to a maximum request rate of 10 requests per second.
2. Weekly Recrawl: Your website is re-scanned on a weekly cadence. This ensures that the internal link graph remains up-to-date, reflecting any changes made to your site's structure or content.
3. Incremental Updates: In addition to the weekly recrawl, LemRank can detect new pages published within 24 hours. Once detected, the internal link graph is rebuilt to incorporate these incremental updates, ensuring that you see the most current state of your site's links.
4. Visualization: The collected data is rendered as an interactive graph. Each page is represented as a node, and internal links appear as arrows indicating the direction of the link. The graph highlights important metrics for each node, such as the number of incoming and outgoing internal links.
5. Issue Flagging: LemRank automatically flags specific patterns within the graph to draw your attention to critical issues and opportunities:
   • Orphan pages: Pages with 0 incoming internal links are clearly marked, helping you identify content that is hard to discover.
   • Potential PageRank Sinks: Pages with 100 or more outgoing internal links are flagged, suggesting further investigation to ensure link equity is not being overly diluted.
6. Drill-down Capabilities: You can click on individual nodes (pages) within the graph to view detailed information about that page, including its URL, title, number of incoming links, and outgoing links. This allows for deep analysis of specific page connections.
7. Filtering and Segmentation: The graph can be filtered by various criteria (e.g., page type, status code, number of links) to focus on specific sections of your site or types of pages.

This visualization tool helps you understand how link equity flows, identify structural problems, and plan strategic internal linking campaigns to improve SEO and user experience.

Related

• What is topical authority
• How to detect content decay