Topical authority and Topical Trust Flow: what they mean for links

Topical authority is the name SEOs give to a site being treated by a search engine as a reliable source on one subject, as opposed to being strong in general. The idea covers both sides of SEO: what the site publishes on the subject, and who links to it and mentions it in connection with that subject. Topical Trust Flow is a metric from the backlink tool Majestic that tries to put a number on the second half, by sorting the trust a site receives through links into subject categories.

Two things matter about the pair. The first is that topical authority is a practitioner term. Google has described a system with a similar name for news, and documents that became public in 2024 and 2025 show that it measures topic at site level, but there is no published general score and nobody outside Google knows how much weight topic carries. The second is that Topical Trust Flow is one vendor’s estimate, built on that vendor’s crawl and categories. It is useful for asking which subjects a site’s links come from, and it should not be read as a view into Google.

What SEOs mean by the term

In everyday use the phrase carries a claim about how sites win rankings. The claim is that a site which covers one subject in depth, and which is linked to by other sites on that subject, will rank for queries in that subject more easily than a larger general site with stronger overall link numbers. People point to specialist sites outranking national newspapers for narrow queries as evidence. The observation is real enough, though it has more than one possible cause, since a specialist page is often simply a better match for the query and may attract better anchors and more satisfied visitors.

The phrase also gets used for a content plan: publish a cluster of pages around a subject, link them together, and authority will follow. That is the on-page half of the idea and sits outside this lesson. The off-page half is the question of whether the topic of the linking site changes what a link is worth, which the site already examines in link relevance versus authority. This page takes the narrower matter of what is known about topic being measured at the level of a whole site, and what a tool can show you about it.

What Google has said on the record

The clearest statement is about news. In a Search Central blog post dated 23 May 2023, titled “Understanding news topic authority” and signed by Jen Granito, a group product manager for Search, Google said it had developed “a system called topic authority” that helps determine which expert sources are helpful for a “newsy query in certain specialized topic areas, such as health, politics, or finance”. The post lists the most prominent signals. One is how notable a source is for a topic or location. Another is influence and original reporting, where the system looks at how a publisher’s original reporting “is cited by other publishers”. The last is source reputation, which includes a history of high-quality reporting and recommendations from expert sources such as professional societies.

Two details in that post deserve attention from anyone who builds links. The second signal is a description of citation by peers on the same subject, which is close to what a link from a relevant site represents, although the post talks about citing and does not say hyperlinks. And the scope is narrow. The post is about news results, Top Stories and local news, and it does not say the system applies to product pages, guides or commercial queries. Reading it as confirmation of topical authority across all of search goes further than the text does.

Outside news, Google’s guidance on creating helpful content, as it stood in October 2026, includes two self-assessment questions that touch the same idea. One asks whether the site has “a primary purpose or focus”. The other asks whether someone who researched the site would come away with the impression that it is “well-trusted or widely-recognized as an authority on its topic”. These are prompts for site owners and say nothing about mechanism, but they show that Google’s public description of a good site includes being known for a subject by people outside it.

What the leak and the court documents add

The site’s lesson on the leak and the antitrust documents grades each finding by how firm it is, and the topical findings fall in the middle grades. The documentation leaked in May 2024 describes measures of a site’s topical focus and of how far an individual page sits from that focus. It also describes a demotion for anchors that do not match their target. Analysts infer from these that topical fit between a linking site and the page it links to matters. The documentation contains no weights and no formulas, so it shows that such things are stored and does not show how, or whether, they are used in ranking.

The court material is firmer and less specific. An exhibit from the US antitrust case, reported in May 2025, describes a topicality score built from anchors, body text and clicks, and a separate quality score that is mostly a property of the site and to which PageRank is an input. That places anchor text and its context on the side of the system that decides whether a page fits a query. It does not describe a site-level topic score fed by links. There is an older research precedent as well: a 2002 academic paper on topic-sensitive PageRank is reported to describe computing PageRank separately for different topics, which shows the idea has been available to search engineers for a long time. Put together, the fair reading is that topic is measured at site level, that relevance signals travel with links, and that the size of any topical bonus is unknown.

How Topical Trust Flow tries to measure it

Majestic’s ordinary Trust Flow is a quality score from 0 to 100. Majestic’s glossary, read in October 2026, says the company “collated many trusted seed sites based on a manual review of the web”, and that sites closely linked to a trusted seed see higher scores. The method is a relative of the academic idea covered in TrustRank and seed sites. Topical Trust Flow applies a subject label to that flow of trust. The glossary describes it as a feature which “provides website categorisation”, giving “a series of numbers, on a log based scale between 0-100”, where each number “shows the relative influence of a web page, subdomain or root domain in any given topic or category”. Dixon Jones, then of Majestic, described it in a Search Engine Journal interview in September 2014 as a way of connecting websites by their relevance to each other.

The point to hold on to is that the topics come from links and not from the words on the page being scored. In the same interview Jones is reported as saying that Majestic keeps data on how websites link to each other and not on-page data. So a site’s topical profile in Majestic is a statement about which subject areas its trust arrives from. Majestic’s Topics report, according to the glossary, lets you see whether a classification comes from links pointing directly at a page or is carried through from links to other pages on the same domain. A page can therefore show a topic it has never written about, because its domain’s links carry that label.

Three limits follow. Majestic’s crawl is its own, and backlink tools disagree about which links exist at all, so the profile is drawn from a partial picture. The categories are Majestic’s, and a site in a niche that the category list handles badly will look scattered or mislabelled. And because the scale is logarithmic, a topic score of 30 against one of 20 represents a bigger gap than the numbers suggest. Like every third-party score it can also be inflated, a subject covered in faked link metrics. Google uses none of these scores, as the comparison of authority metrics explains.

Reading a topic profile before you buy or pitch

Used with those limits in mind, the topic profile answers a question the headline authority numbers cannot: what a site is known for, in the view of the sites linking to it. Picture a small firm that sells booking software to veterinary practices. It is offered two placements at the same price. One is on a general business blog with a high authority score, whose top topics in Majestic are spread across shopping, gambling, travel and health in roughly equal measure. The other is on a modest site for practice managers, whose trust arrives mostly from animal health and small business categories. Nothing in the tool says which link Google will value more, but the second profile describes a site with a subject and the first describes a site that takes links from, and probably sells links to, anyone.

The same reading catches a second problem. When a domain has changed hands, the old links keep their labels. A site that now publishes about personal finance while most of its trust arrives from, say, a regional sports category is likely to be a repurposed expired domain, and the domain history checker or the web archive will usually confirm it. This mismatch between what a site says it is and what its links say it is deserves more attention than any single score. It is also one of the criteria in the fuller process for vetting a publisher, where topical relevance is checked at domain, section and page level alongside traffic and outbound links.

What this means for choosing link sources

None of what follows is measured. It is a working method that fits the evidence above and the two-score picture from the court exhibit. Because the confirmed relevance signal is anchor text and the content around it, the page that links to you matters most, then the section it sits in, then the site as a whole. A relevant article on a general news site can therefore be a good link, and an off-topic article on a specialist site is a weaker one than the site’s profile suggests. Topical Trust Flow describes the site and its links, so it works best as a filter applied early in link prospecting, before anyone reads individual pages.

The checks can be run in a fixed order on any candidate, and the order saves time because the early ones remove most poor candidates.

1. Read the site’s main sections and recent posts, and state its subject in one sentence. If that is impossible, stop.
2. Compare that subject with the top topic categories in Majestic or another backlink tool.
3. Check the keywords the site ranks for against the same subject.
4. Look at the specific page or section where the link would sit, and at what else it links to.
5. Ask whether a reader of that page would have any reason to click through to yours.

The method has a known weak spot, which is that it can make a campaign too narrow. A profile in which every link comes from one tight subject category is unusual for a real business, since real businesses are also mentioned by local press, suppliers, trade bodies and general news. Digital PR earns links mainly from news sites whose topical profile is broad by nature, and those links feed the trust side of the picture even when the topical side is thin. The practical position is to treat topical fit as a reason to reject sites that have no subject at all, and as a tie-breaker between otherwise similar candidates, while accepting editorial coverage from strong general sites when it comes. Anyone who quotes a percentage of links that must be on-topic is supplying the figure themselves, because no source for one exists.