"Get relevant backlinks" is standard SEO advice. But relevance is not binary — Google uses multiple distinct relevance signals to weight how much authority a link transfers and how much topical relevance signal it provides. Understanding the layers of relevance calculation reveals why some apparently relevant links barely move rankings while others from less obvious sources produce dramatic improvements.
Page-Level vs Domain-Level Relevance
Relevance operates at two independent levels, and most link building focuses on only one. Domain-level relevance — whether the linking domain covers your topic area generally — is the level most practitioners evaluate. But page-level relevance — whether the specific page containing the link is about your specific topic — is a stronger signal.
A link from a general marketing blog's article specifically about broken link building is more topically relevant to a broken link checker tool than a link from an SEO-specific blog's article about social media strategy. The page covering your specific topic provides stronger relevance signal than a topically relevant domain that happens to link from an unrelated article.
As we covered in our guide to niche relevance in link building, this explains why page-level context matters — aim for links from pages that are specifically about topics closely related to your linked content, not just from domains that are generally in your industry.
Semantic Relevance Beyond Exact Topic Match
Google's semantic understanding means relevance extends beyond exact topic match. A link from an article about website performance to a page about broken link checking is semantically relevant — broken links affect performance — even though "performance" and "broken links" are not identical topics.
This semantic relevance is calculated based on the co-occurrence of entities and concepts in the linking page's content and the linked page's content. Articles that mention similar entities (website tools, SEO, technical auditing) as your target page provide relevance signal even if they cover a slightly different specific topic.
The practical implication: do not restrict link building outreach to only exact-topic matches. Sites covering adjacent topics within your semantic neighbourhood provide genuine relevance signal. A web development blog, a startup growth blog, and a digital marketing blog all have semantic relevance to an SEO tools site even though none of them is specifically an SEO blog.
Co-Citation and Co-Occurrence Effects
Co-citation occurs when two sites are both linked to from the same third-party sources without linking to each other. Google uses this as a relevance signal — if sources A, B, and C all link to both your site and Competitor X, Google infers topical proximity between your site and Competitor X based on this shared citation pattern.
The SEO application: when doing link building outreach, targeting sites that already link to your strongest competitors is not just a tactical decision (they are pre-qualified as willing linkers in your niche) — it is a relevance-building decision. Acquiring links from the same sources as your topical competitors strengthens your topical relevance signal through co-citation effects.
Anchor Text and Contextual Relevance
As we covered in our guide to anchor text variations, the anchor text used in a link is a relevance signal — not just for the keyword it contains but for the topical context it creates. A link with the anchor "free broken link checker tool" surrounded by paragraph text about website maintenance creates richer topical context than the same anchor surrounded by unrelated content.
The surrounding text (typically the paragraph containing the link) contributes to the relevance calculation. Google uses this surrounding context to understand what the link is endorsing — a link from a paragraph about technical SEO tools provides more relevant topical signal than a link from an author bio or footer navigation, even with identical anchor text.
The Topical Trust Flow Concept
Majestic's Topical Trust Flow metric attempts to measure this principle — but the underlying concept applies regardless of the tool. Authority does not flow equally in all directions: it flows more strongly along topical lines. A high-authority SEO publication linking to your SEO content passes more relevant authority to that page than the same publication linking from a tangentially related article about digital marketing generally.
Summary
Backlink relevance is calculated at page level (more specific) and domain level (broader), through semantic entity co-occurrence beyond exact topic matching, through co-citation patterns that establish topical proximity, and through contextual anchor text and surrounding content. Prioritise links from specifically relevant pages over generally relevant domains, pursue links from sources that cite your competitors, and use our anchor text analyser to monitor the contextual relevance signals in your growing backlink profile.
Continue reading: SEO for Online Marketplaces: Ranking Listing Pages and Building UGC Authority