Glossary
What is topical authority? A plain definition.
Subject authority means covering a topic so completely that search engines and AI assistants treat you as a reliable source on it. Here is how it works and how to build it.
Short answer
What is subject authority?
Topical authority is the trust a site earns by covering one subject in depth with original, accurate, connected content. Google says trust is the most important E-E-A-T aspect, though E-E-A-T itself is not a specific ranking factor.
In brief
Four things to know first.
Depth beats volume
Authority comes from covering a subject well, not from publishing many thin pages.
It is not a Google score
Google says no secrets will automatically rank a site first. Its AI features add no technical requirements, and Google names no ideal page length.
Trust sits underneath
Google says trust is the most important E-E-A-T aspect, and the others contribute to it.
AI uses the same base
Google's AI features rest on its core ranking and quality systems, so the work carries over.
Definition
Topical authority, in plain words.
This is the standing a site builds on one subject. You cover its main questions, link the pages together, and show real expertise. Search engines and assistants then have reason to rely on you.
The term is industry shorthand. Google lists the “expertise of sources” among the factors its ranking algorithms look at, but it describes no single authority score.
| Subject authority | Thin coverage | |
|---|---|---|
| Scope | Many related questions on one subject | A few pages on many subjects |
| Content | Original, accurate, expert-led | Common knowledge anyone could write |
| Structure | Pages link to each other by topic | Isolated pages with no clear path |
| Effect | A reason to trust you on the topic | No reason to pick you over others |
How it works
What search engines actually weigh.
Google says its systems prioritize content that shows expertise, authoritativeness and trustworthiness. One quality factor is whether other prominent websites link to or refer to your content.
Google also says unique, compelling, useful content will likely matter most for presence in AI search over the long run. It contrasts that with commodity content built on common knowledge.
Expertise of sources
Google names it among the factors its algorithms weigh when ranking results.
References from others
Links or mentions from prominent sites are generally a good sign the information is trustworthy.
Trust above all
Google says trust is the most important E-E-A-T aspect, and E-E-A-T is not itself a ranking factor.
Non-commodity content
Original takes and real experience set a page apart from advice anyone could write.
AI answers
Why it matters in AI answers.
Google's AI features rely on its core Search ranking systems to retrieve relevant pages. Google's guide says SEO best practices continue to be relevant for them.
Query fan-out, where the model runs several related searches, rewards sites that answer the neighbouring questions too. Assistants return one answer with a few sources, so a brand that is not cited is not considered.
Why it matters in AI answers.
Google's AI features rely on its core Search ranking systems to retrieve relevant pages. Google's guide says SEO best practices continue to be relevant for them.
See where you stand on your subject
We run your buyers' questions in ChatGPT, Claude, Perplexity and Gemini and show where you are cited and where rivals are.
What to do
How to build topical authority.
Pick one subject you can speak on with real expertise. Build outward from the questions buyers ask, and check the result in the assistants they use.
Choose your subject
Pick the subject where you have real experience and a clear buyer need.Map the questions
List what buyers ask, including the related questions around each main one.Answer each in depth
Write original pages with specific facts and expert detail, not common knowledge.Link pages together
Connect related pages so people and crawlers can move through the whole subject.Earn references elsewhere
Be useful on the sites and communities your buyers read. Do not chase inauthentic mentions.Measure the result
Track citations for your agreed questions in each assistant, against a baseline.
FAQ
Topical authority: common questions.
Does Google use a subject authority score?
Google says its AI features have no additional technical requirements and that SEO best practices stay relevant. Google names no ideal page length. You need no special schema.org markup for generative AI search either.
How many pages do you need to build subject authority?
No page count creates it. Google says it has no preferred word count and warns against writing to one. What matters is covering the subject's real questions with original, accurate pages, not reaching a target number.
Is subject authority the same as E-E-A-T?
Subject authority is not the same as E-E-A-T. E-E-A-T is Google's framework of experience, expertise, authoritativeness and trust, and Google says trust is the most important aspect. E-E-A-T itself is not a specific ranking factor.
Do AI assistants care about subject authority?
AI assistants favor sources they can trust on a question. Google says its AI features rest on its core ranking and quality systems, so the same depth and quality apply. Which sources each assistant picks still differs, so check each one.
Can AI-written content build subject authority?
AI-written content can support this work only if it adds real value. Google says producing many pages with generative AI without adding value may break its scaled content abuse policy, and asks you to fact-check AI output before publishing.
Find out if AI trusts you on your subject.
We run your buyers' questions through ChatGPT, Claude, Perplexity and Gemini and show you the gap.