Internal Linking: The Underrated SEO Win

Internal linking is the only part of link-based SEO you fully control, and it is also the part with the highest ratio of folklore to documentation. Click depth thresholds, link equity sculpting, optimal links per page, crawl budget anxiety: almost none of it appears in anything Google has published. What Google does document is narrow, specific, and enough to work from.

What the documentation actually says

Three statements carry most of the weight. First, from Google’s Link best practices page: “Google uses links as a signal when determining the relevancy of pages and to find new pages to crawl.” Second, from the same page, a technical constraint: “Generally, Google can only crawl your link if it’s an <a> HTML element with an href attribute,” and the href must resolve to something resembling a real URI. Third, from the sitemaps documentation: “If your site’s pages are properly linked, Google can usually discover most of your site.”

That third sentence is the case for internal linking in its entirety, made by Google. The sitemaps page goes further and says you might not need a sitemap at all if your site is small, meaning around 500 pages or fewer, and comprehensively linked internally so Googlebot can reach every important page by following links from the home page. It also warns that a sitemap “doesn’t guarantee that all the items in your sitemap will be crawled and indexed.” Listing a page in a sitemap is not a substitute for linking to it.

The technical constraint is where real sites break. Modern component libraries make it easy to ship navigation as a div or span with a click handler, or an href of javascript:goTo(). Google lists those exact patterns as not recommended and says it may not extract them. Google does confirm that links inserted with JavaScript are crawlable as long as the rendered markup is a proper anchor with an href, so the fix is usually a markup change rather than an architecture change. Check it with the URL Inspection tool rather than assuming.

Anchor text, per Google rather than per Twitter

Google defines anchor text as the visible text of a link and says it “tells people and Google something about the page you’re linking to.” Its guidance is that good anchor text is descriptive, reasonably concise, and relevant both to the page it sits on and the page it points to. The documentation gives an unusually useful self-test: read only the anchor text, out of context, and check whether it is specific enough to make sense by itself. “Click here,” “read more” and “website” fail that test, and so does an entire sentence used as a link.

Google also documents the fallbacks. If an anchor element is empty, it can use the title attribute as anchor text. For an image used as a link, it uses the img element’s alt attribute as the anchor text, which makes descriptive alt text on linked images an internal linking task rather than only an accessibility one. And it advises against chaining links directly next to each other, on the grounds that readers cannot distinguish them.

What Google does not publish is a keyword formula. Its anchor text guidance warns that keyword stuffing violates its spam policies, and notes that the words before and after a link matter, so the sentence as a whole is what is being read. Optimising internal anchors toward exact-match keywords is not supported by the documentation and produces text that fails Google’s own out-of-context readability test.

Claims worth retiring

What to actually do

1. Verify every navigation and in-content link renders as an anchor element with a resolvable href. Confirm with the URL Inspection tool, not by reading the source of your component.
2. Find pages with no internal links pointing at them. These are the genuine orphans, and a sitemap entry does not compensate.
3. Rewrite anchor text that fails the out-of-context test. If reading the link text alone does not tell you what the page is, it is not doing its job.
4. Add descriptive alt text to every image that functions as a link, since Google uses alt as the anchor text there.
5. When you publish, link to the new page from the existing pages it is genuinely relevant to, and link out from it to the established pages it depends on.

The pillar-and-cluster structure is worth using, but for an honest reason rather than the usual one. There is no documented “topical authority” signal you switch on by arranging pages in a hub. What a hub does is guarantee that every subtopic page has at least one contextual link from a relevant page, that the anchor text describing it is written deliberately, and that a reader who lands anywhere in the group can reach the rest. Those are the documented mechanisms. The structure is a reliable way of producing them, not a signal in itself.

Daniel Okafor

SEO & Organic Growth Lead

Daniel Okafor leads SEO and organic growth at ThisCom, helping small and medium businesses earn authority through technical SEO, content, and high-quality links.

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