On this page8 sections
Why it matters for founders and small teams
A small team can’t outrank a category leader on its head term, but it can become the most complete source on a narrow slice of the subject — the kind of depth search engines and AI systems reward. Topical authority turns a limited publishing budget into a strategy: pick the subject your buyers care about, cover it thoroughly, and stop spreading effort across topics that never feed your pipeline.
Does Google use topical authority?#
Google has confirmed a “topic authority” system only for news, explained in a May 2023 post; for the wider web it has published no topical-authority score, though its helpful-content guidance asks whether a site has “a primary purpose or focus” and warns against publishing on many unrelated topics.
Google’s news topic authority system surfaces expert publications for newsy queries in areas such as health, politics and finance. Its example: people looking for Nashville high school football news often turn to The Tennessean. For every other kind of site, the evidence is indirect.
Topic authority for news
OfficialGoogle weighs how notable a publication is for a topic or location, how often other publishers cite its original reporting, and its history of high-quality reporting.
Site focus in Google's guidance
OfficialGoogle’s helpful content questions ask “Does your site have a primary purpose or focus?” and flag “producing lots of content on many different topics in hopes that some of it might perform well” as a warning sign.
Site-focus attributes in the 2024 leak
Our readGoogle API documentation leaked in 2024 listed
siteFocusScore— “how much a site is focused on one topic” — andsiteRadius. They suggest focus is measured somewhere, but Google hasn’t confirmed how, or whether, they’re used.
The news post ends with advice that generalizes well: publishers should “provide great coverage about the areas and topics they know well.”
Does topical authority matter for AI search?#
Topical authority matters for AI search because engines fan one question out into many sub-questions and cite whichever pages best answer each one — so a site that covers a subject’s follow-up questions gets more chances to be cited than a single strong page on the head term.
Google describes AI Overviews and AI Mode issuing “a set of concurrent, related queries” — its example turns a question about a weedy lawn into separate searches about herbicides, chemical-free removal and prevention. Each sub-query has its own winners. That is why so many cited pages don’t rank for the question the user typed. See query fan-out.
37.9%
of pages cited in Google AI Overviews rank top 10 for the query the user typed
7.61
ChatGPT fan-out searches per prompt after August 2026, up from 2.17
~0.19
correlation between a site's page count and AI brand visibility — “almost no relationship”
Worked example
The Focus-and-Depth Check
Two ratios that show whether your publishing builds authority or scatters it: how much of what you publish stays on your core subject (focus), and how much of that subject you have actually answered (depth). The inputs below are illustrative, for a fictional project management tool called Plannora.
- 1
Posts published in the last year
Every blog post and guide on the site.
60
- 2
Posts on the core subject
Project management for small agencies. The rest are generic productivity tips, remote-work listicles and company news.
21
- 3
Focus ratio
21 ÷ 60 — the share of publishing effort spent on the subject Plannora wants to own.
35%
- 4
Subtopic questions mapped
What buyers ask about the subject: setup, templates, pricing models, client reporting, resourcing, comparisons and more.
40
- 5
Questions with a page that answers them
Several of the 21 on-topic posts overlap, so together they answer 12 distinct questions.
12
- 6
Depth ratio
12 ÷ 40 — the share of the subject a searcher, or an engine’s fan-out, can find answered on the site.
30%
- =
Authority gap
40 − 12 unanswered questions to cover before publishing anything off-topic.
28 questions
The result: Plannora’s problem isn’t volume — five posts a month — but aim: almost two-thirds went off-topic. Pointing the same budget at the 28 unanswered questions would take depth to 100% in under six months without publishing a single extra post. Recompute both ratios every quarter.
Free to use and adapt. If you cite it, link to rankbox.xyz/glossary/topical-authority.
How do you build topical authority?#
Build topical authority by choosing one subject your buyers care about, mapping every question they ask about it, answering each in a page or clearly headed section, linking those pages into a cluster, and earning references from other sites in the same field.
- Draw the boundary. One subject tied to what you sell — “project management for small agencies,” not “productivity.” Say no to posts outside it, however easy they look.
- Map the questions. Definitions, how-tos, comparisons, pricing, troubleshooting, alternatives — plus the follow-ups an AI engine would search on the buyer’s behalf.
- Answer each one properly. A page or clearly headed section per question, answer-first, with first-hand detail a generic page lacks.
- Wire it together. A pillar page that links to every subtopic page and back — a topic cluster held together by internal links.
- Earn outside references. Google’s news system weighs how often others cite a publisher’s work; on the wider web, backlinks and brand mentions from sites in your field are the nearest equivalent.
- Keep it current and tidy. Refresh pages as facts change, and merge overlapping ones before they compete with each other.
Topical authority vs domain authority: what's the difference?#
Domain authority is a third-party score of a whole site’s link strength across every subject; topical authority is how trusted a site is on one specific subject — so a small specialist site can be the stronger source on its own topic than a high-scoring generalist.
| Domain authority | Topical authority | |
|---|---|---|
| What it measures | Backlink strength of the whole domain | Depth and recognition on one subject |
| Who defines it | Moz, Ahrefs, Semrush — not Google | No public score; Google confirms a news version |
| How you raise it | Earning links from strong sites | Covering a subject completely and being cited for it |
| Carries across topics? | Yes, the score is site-wide | No — authority on CRM says nothing about recipes |
| Link to AI visibility | Weak: Domain Rating correlated 0.27 with ChatGPT brand visibility | Plausible through fan-out, which rewards subtopic coverage |
See domain authority. The practical difference for a small team: a high Domain Rating takes years of links to build, while depth on a narrow subject is within reach of anyone who publishes steadily on it.
How do you measure topical authority?#
Measure topical authority indirectly, since no tool can read Google’s assessment: track how many of a subject’s mapped questions your site answers, how visible you are across that whole group of queries and prompts, and how often other sites in the field reference you.
- Coverage: the share of mapped subtopic questions that have a page answering them. The worked example below shows the arithmetic.
- Visibility across the cluster: impressions and rankings in Search Console for the whole group of queries, not one head term.
- AI citations for the topic: in prompt tracking, the share of subject-related prompts where engines cite or name you, against competitors.
- Outside references: new referring domains and mentions from sites in the same field.
Related terms#
- Content & relevanceTopic clusterA group of interlinked pages on one subject — a broad pillar page linked to and from narrower pages on each subtopic — built to show search engines and AI retrieval systems complete coverage of the topic rather than a single article.Read the entry
- Authority & off-siteInternal linkingThe practice of linking between pages on the same website, which helps crawlers find pages, moves authority from strong pages to weaker ones and shows search engines and AI systems how the topics on a site relate.Read the entry
- How LLMs answerQuery fan-outAn AI search technique in which the engine rewrites one user question into several narrower sub-queries, runs them in parallel and builds its answer from the combined results — which is why a page can be cited for a prompt it doesn’t rank for.Read the entry
- Authority & off-siteE-E-A-TThe framework Google’s search quality raters use to judge whether content is credible, with trust at its center; it is not a single ranking factor but a description of what Google’s systems aim to reward.Read the entry
- DAAuthority & off-siteDomain authorityA third-party score from 1 to 100, created by Moz, that predicts how well a website is likely to rank based mainly on its backlinks; Google does not use it, and comparable metrics include Ahrefs’ Domain Rating and Semrush’s Authority Score.Read the entry
- Authority & off-siteEntity SEOThe practice of making search engines and AI models recognize a brand, person or product as a distinct, well-described thing — an entity with consistent facts and relationships — rather than a string of keywords, so it can be tied to the topics it should be recommended for.Read the entry
Go deeper
Sources
- 1.Understanding news topic authorityGoogle Search Central Blog · developers.google.com ↗
- 2.Creating helpful, reliable, people-first contentGoogle Search Central · developers.google.com ↗
- 3.Optimizing your website for generative AI featuresGoogle Search Central · developers.google.com ↗
- 4.How many AI Overview citations rank in the top 10?Ahrefs · ahrefs.com ↗
- 5.Top brand visibility factors in ChatGPT, AI Mode and AI Overviews (75K brands studied)Ahrefs · ahrefs.com ↗
- 6.ChatGPT tripled its fan-out queriesNectiv · nectivdigital.com ↗
- 7.Secrets from the Google algorithm leakiPullRank · ipullrank.com ↗
