AI search glossary
Topical authority: what it is and how Google describes it
Topical authority is the degree to which a site is recognised as an expert, go-to source on a particular subject, shown by deep coverage of that subject, original work, and citations and recommendations from others.
Also called: topic authority, topical relevance
Why it matters for AI search
When an AI engine needs a source for a specialist question, it leans on sites that consistently cover that subject and that other sources cite. A site with twenty solid pages on one topic is a more likely citation than a general site with one page on it. Topical authority is how a small, focused site competes with large generalists in AI answers.
What Google has actually said
The term is common in SEO, but Google has described one specific system. In May 2023 it explained a topic authority system for Google Search and News that helps identify which expert sources are helpful for a newsy query in specialised areas such as health, politics or finance. Google listed its most prominent signals:
- Notability for a topic or location: publications especially relevant to a subject or place, such as a local paper for local high school sports.
- Influence and original reporting: how often other publishers cite a source's original reporting.
- Source reputation: a history of high-quality work, recommendations from expert sources such as professional societies, and awards.
Google's advice to publishers was simple: keep providing great coverage of the areas and topics you know well.
The broader SEO meaning
Outside news, "topical authority" describes the same idea applied to any site: a site that covers one subject in depth, with original insight and links from others in that field, tends to be treated as a reliable source for it. Google's helpful content guidance points the same way: it asks whether content shows first-hand expertise and depth, and whether the site has a primary purpose or focus.
How to build it
- Pick a subject you can own. Narrow enough that you can cover it better than anyone.
- Map the questions. Beginner, comparison, cost, troubleshooting and advanced questions all belong in the map.
- Publish original material. Data, tests, case results and opinions only you can give. Original work is what others cite.
- Link the pages together so engines and readers see the subject's structure.
- Earn citations. Mentions from respected sites in your field are the outside proof of authority (see brand mentions).
- Stay on topic. Unrelated posts written to catch traffic dilute what the site is known for.
Topical authority and AI answers
AI engines pick a handful of sources per answer. A site known for a subject has more pages that match an engine's sub-questions and more outside sources pointing at it, both of which raise the odds of AI citations. Check whether engines such as Perplexity cite you for questions in your niche. Topical authority is closely related to E-E-A-T, and it is built through semantic SEO: complete, connected coverage of a subject.
Questions
- Does Google have a topical authority ranking factor?
- Google has publicly described a topic authority system for news. It helps decide which expert publications are helpful for newsy queries in specialised areas such as health, politics or finance, and for local news. Google has not published an equivalent system for all searches, though its general guidance rewards depth and expertise.
- How many articles do I need for topical authority?
- There is no published number. What matters is that the important questions in your subject are answered well, and that the pages link to each other sensibly. A few thorough pages beat many thin ones.
- Can a new or small site build topical authority?
- Yes, by narrowing the subject. A small site can become the best source on a specific niche long before it could compete on a broad one. The GEO research also found that lower-ranked sources can gain the most visibility in AI answers from clear, well-sourced content.