Topical authority is the recognition by search engines and AI engines that a site is the place to go for a specific subject. Not a single metric — a composite reputation built over time from content depth, citation patterns, and editorial behavior.
Signals that compound into topical authority:
- Depth of content on the subject — many pages covering the topic from different angles, not one shallow overview
- Internal linking density within the topic cluster — the pillar page and supporting pages cite each other coherently
- External citations from other authoritative sources in the same space
- Author bylines with demonstrable expertise (the EEAT lever)
- Time — newer sites accumulate authority more slowly, even with strong content
Topical authority vs. domain authority
Domain authority is broader — the site's overall reputation. Topical authority is sliced by subject. A site can have high domain authority and weak topical authority on a specific subject (a generalist news site writing one piece about quantum computing), or the inverse (a niche blog with deep coverage of one subject but unknown elsewhere).
AEO is increasingly subject-specific. AI engines pick the source with the strongest topical authority for the specific question, not the strongest domain authority overall.
Why it matters for AEO
Topical authority is the single biggest predictor of whether AI engines will cite you on a question. The model "knows" — through training on the citation graph + editorial signals — which sites have depth on which subjects.
What b/cited does about it
- Authority Score (the b/cited metric) is the quantified proxy: clusters × ownership × content density
- Briefs suggest content gaps that would deepen authority on existing clusters rather than diluting attention across new subjects
- Internal linking suggestions strengthen the topical structure that search engines read as "this site has organized depth here"