Internal linking is the most underused lever in SEO. External links from other sites are hard to earn (you need outreach, budget, time). Internal links are between your own pages, and you control them 100%. Yet correct internal linking lifts rankings 20–40% even without new external links. This article walks through why internal links matter, how to distribute PageRank between pages, how to pick anchors, and how to audit your existing internal links.
What PageRank is and how it flows
PageRank is Google's algorithm scoring page "authority". Every external link to your page passes PageRank. Every internal link from one of your pages to another passes PageRank between your own pages. More PageRank = higher rankings. Key idea: if you earned a quality external link to the homepage, that link passes PageRank to the homepage. The homepage then shares this PageRank with other site pages via internal links. With 10 links on the homepage, each gets 10% of PageRank. With 100, each gets 1%. This is called PageRank "dilution". Strategy: concentrate links on the most important pages.
Hubs and authority pages
A hub is a page that receives many internal links (input) and selectively passes them onward (output). The homepage is the biggest hub. Catalogue categories are second-tier hubs. Pillar pages are third-tier hubs. Strategy: concentrate external links on hubs, redistribute PageRank from there to priority pages via carefully chosen internal links. Simple pattern: a hub links to 20–50 key topic pages, and those pages link back to the hub. This creates a "star" with the hub at the centre. Google reads the structure and treats the hub as an important page on the topic.
Anchor strategy
Anchor is the visible link text. Google uses anchors to understand what the target page is about. Rule: anchors must be diverse but always topical. If all 100 internal links to an article use the anchor "site rank monitoring", that looks spammy — Google downgrades. If diverse: "how to track positions", "monitoring tool", "rank-tracking guide", "our position checker" — natural, encouraged. What you can't do: "click here", "more", "this". Weak anchors carrying no information. Better: "the complete guide to rank monitoring" — carries the keyword and a clear description.
Contextual links vs navigation links
Not all internal links carry equal weight. A link from inside an article body ("the full domain migration guide here") is stronger than a link in navigation or sidebar. Google considers contextual links more natural — the author chose to embed them. Navigation links are uniform across all pages and algorithmically less valuable. Strategy: add contextual links inside the body of every article to relevant other articles. Minimum 3–5 contextual links per medium-size article. Site Metrics Tool auto-proposes contextual links between related blog posts via the related-posts block plus manual additions in the main text.
Auditing existing internal links
Full Screaming Frog crawl → "Inlinks" report per page. What to look for: pages with 0 internal inbound links (orphans) — critically bad, urgently add links; pages with 1–2 — weak, worth strengthening; pages with the imbalance "many outbound, few inbound" — they're leaking PageRank. Additional check: pages getting GSC traffic should have many internal links (5–10 minimum) — they're the "gold reserve" to defend. For sites with 1,000+ pages a specialised audit with internal-link graph visualisation helps.
Frequently asked
How many internal links should a page have?
Depends on page type. Homepage 30–80, category 20–50, blog post 5–15 contextual, product card 8–15. Too many — PageRank dilutes.
Do I need nofollow on internal links?
No. Nofollow used to be used to "preserve" PageRank, but in 2019 Google changed it to a "hint" — it no longer blocks PageRank pass-through. Nofollow on internal links is meaningless.
Does Site Metrics Tool help with internal linking?
On the blog — yes, we auto-propose related posts by tags and show a sidebar linking to tools. A full internal-link audit needs crawling — on the Q1 2027 roadmap.