Yandex's IKS (its site quality index), Majestic's Trust Flow and Citation Flow, Ahrefs' Domain Rating and Ahrefs Rank, and Semrush's Authority Score all get called "site authority", and they are all different numbers calculated from different data. Yandex builds IKS from how people use its services. DR and Trust Flow describe links and nothing else. Authority Score mixes links with a traffic estimate. So the same site can have a modest IKS and a high DR without any contradiction. Below is a short account of what each metric measures, what it cannot see, and how to read them together when you are judging a link source, a competitor or your own project.
Six numbers in one table
Before taking them one at a time, it helps to see them side by side. Every definition comes from the vendor's own help pages, checked 15 October 2026.
| Metric | Vendor | Scale | Built from |
|---|---|---|---|
| IKS (ИКС) | Yandex | not fixed | audience size, user satisfaction, trust from users and from Yandex |
| Domain Rating (DR) | Ahrefs | 0–100 | a domain's backlink profile relative to every other site in the database |
| Ahrefs Rank (AR) | Ahrefs | a rank position, 1 is best | the same link data as DR, without the rounding |
| Citation Flow (CF) | Majestic | 0–100 | how many links a site has and how much "power" they carry |
| Trust Flow (TF) | Majestic | 0–100 | closeness to sites Majestic reviewed by hand as trustworthy |
| Authority Score (AS) | Semrush | 1–100 | links, estimated organic traffic and spam signals |
Only IKS is calculated by a search engine, and only IKS draws on data about users. The other five come from third-party services working from their own link indexes. Yandex and Google do not see those numbers and do not use them for ranking.
Yandex IKS: how useful Yandex thinks a site is
Yandex's help defines IKS as a measure of how useful and convenient a site is for its users. The calculation takes in audience size, how satisfied users are, and how far users and Yandex trust the site; Yandex gives these as examples of its criteria, not a full list (yandex.ru/support/webmaster, checked 15 October 2026). The formula is not published.
A few practical points follow from the help pages.
- IKS is recalculated regularly, with no fixed schedule. You can subscribe to recalculation notices in Webmaster.
- The main mirror, secondary addresses and subdomains are scored separately and can differ. A blog on a subdomain does not inherit the main site's IKS.
- The score moves with the seasons. A site with seasonal demand can lose IKS in winter and get it back in summer without a single change to the site.
- Yandex reserves the right to reset the score to zero or withdraw it entirely if it finds violations or attempts to influence it.
- A site that appeared in search recently may not have a score yet.
You can see your own site's IKS in Yandex Webmaster, on the My sites page and under quality indicators. For any other site, the site information page shows it once you enter the address. Where Yandex has too little data, you get a dash instead of a number.
The help never says IKS affects rankings; it is Yandex's report on how a site looks from where Yandex stands. IKS also knows nothing about Google. A site that gets nearly all its traffic from Google can have a low IKS and be doing perfectly well.
Links are not among the IKS criteria Yandex names. Buying links "for IKS" is therefore pointless, and a jump in IKS after a link purchase is more likely to coincide with the season or with audience growth.
Ahrefs DR: the strength of a backlink profile
Domain Rating shows the strength of a website's backlink profile compared with the other sites in Ahrefs' database, on a 100-point scale (help.ahrefs.com, checked 15 October 2026). It is built from linking domains and their own ratings. Traffic, domain age and brand recognition play no part.
Two properties of DR matter in any comparison. It is relative: a site can lose a couple of points without losing a single link, simply because the rest of the database grew. And the scale is uneven: going from 20 to 30 is much easier than going from 70 to 80.
How the calculation works, why DR falls while a profile stays put, and which decisions it can support are covered in our article on how Domain Rating is calculated and when to trust it. Where DR sits among Ahrefs' other metrics, and where the service gets its data, is in our overview of what Ahrefs does and where it fits in a Yandex project.
Ahrefs Rank: the same order without the rounding
AR is a site's position in Ahrefs' overall ranking of every site in its database by backlink strength, so a smaller number is better. Ahrefs' DR help itself calls DR a less granular version of AR (help.ahrefs.com, checked 15 October 2026): a huge number of sites share each DR point, and AR keeps the order inside it. How to read that upside-down scale, and when AR tells you more than DR, is explained in what Ahrefs Rank is and how it differs from DR.
Trust Flow and Citation Flow: Majestic's two axes
Majestic describes a link profile with two numbers, which is the clearest difference between it and Ahrefs. Citation Flow, in Majestic's glossary, is a score from 0 to 100 that measures the link equity, or "power", a website or link carries, and predicts how influential a URL might be based on how many sites link to it. Trust Flow, also 0 to 100, is based on quality: Majestic assembled a set of trusted seed sites through a manual review of the web, and the closer a site is to those seeds in the link graph, the higher its Trust Flow (majestic.com/help/glossary, checked 15 October 2026).
On their own, neither number says much; the pair is what is useful. If Citation Flow is well above Trust Flow, the site has plenty of links but few of them come from anywhere connected to the trustworthy part of the web. Profiles built from directories, comment spam and site networks look like that. If the two numbers are close, the links mostly come from ordinary, healthy places. Majestic does not prescribe a ratio, so treat any "correct proportion" you read elsewhere as the author's opinion.
Majestic also has Topical Trust Flow, which is Trust Flow broken down by subject category. It answers a question no other metric on this list asks: which topic a site is influential in. When you are vetting a link source, that matters more than the headline number. A construction site with strong Topical Trust Flow in its own category is worth more to a home renovation site than one with the same overall Trust Flow earned in sports betting.
Majestic runs two indexes as well. Fresh holds recently crawled links and is updated throughout the day; Historic keeps the record back to 2006. TF and CF differ between them, so compare sites within one index.
Semrush Authority Score: links plus traffic
Semrush describes Authority Score as a compound metric that grades the overall quality of a website or a web page, on a scale of 1 to 100. It has three components: link power (the quality and quantity of backlinks), organic traffic (an estimated monthly average) and spam factors, which Semrush calls the naturalness of the profile. Semrush updates the score for every domain once every two weeks (semrush.com/kb, checked 15 October 2026).
The traffic component brings Authority Score closer to a site's "overall weight" than DR or Trust Flow, but for projects that live in Yandex it is also the weak spot. Semrush estimates traffic from its own keyword database and Google positions. A site that lives on Yandex traffic gets an underestimate in that component, and its Authority Score ends up lower than a comparable Google-focused site's. How the two platforms' data differs in general is covered in our Semrush vs Ahrefs comparison.
The naturalness component earns its place differently: it pulls the score down when the link picture looks artificial. It is one of the few built-in attempts to separate honestly earned weight from manufactured weight, though Semrush does not disclose the algorithm.
What none of these metrics measure
Some questions none of these numbers can answer.
- Whether a site will rank for a given query. Rankings depend on the page, how well it matches the query and who else is in the results; a domain-level number accounts for none of that.
- Whether the search engine sees the same links. Each service crawls the web with its own robot, and no link index matches what Yandex or Google knows.
- Whether the site is under a penalty. A site filtered by Yandex can keep a high DR for months, because Ahrefs knows nothing about the filter.
- How many real visitors the site has. Even the traffic part of Authority Score is calculated from search positions.
- How good a topical fit a site is as a link source, with the exception of Topical Trust Flow.
Authority metrics are good for rough sorting and for watching how your own site changes over time. Deciding on a link purchase or a strategy from any single one of them is risky.
Reading the metrics together
These numbers say the most when they disagree. A few common combinations and what usually lies behind them:
| Pattern | What it usually means |
|---|---|
| High DR, low IKS | Lots of links, little audience from Yandex. Possibly bought links, a Google-focused site, or trouble with Yandex. Check traffic and Yandex visibility. |
| High IKS, low DR | A live site with an audience that few others link to. Typical of regional media, online services and strong brands. |
| Citation Flow far above Trust Flow | Many links from weak sources: directories, comments, site networks. Doubtful as a link source. |
| High DR and Trust Flow, low Authority Score | A strong profile with little estimated traffic. For a Yandex-focused site this may be Semrush's blind spot rather than a real problem. |
| Every metric rising, traffic flat | Links are arriving, but at the wrong pages or of the wrong kind. Time to check where they point. |
When comparing competitors, domain metrics help you spot a different weight class. If every site in the top 10 for a query has DR above 60 and yours has 15, the page copy is not the issue. After that, look at the specific pages in the results; how to pick competitors and what to compare is covered in our guide to competitor analysis in the search results.
Domain metrics describe a whole site, while the results are a contest between pages. Most services have page-level scores too. Ahrefs calculates URL Rating, which per its help shows the strength of a page's link profile on a 100-point scale (help.ahrefs.com, checked 15 October 2026). Semrush computes Authority Score for both sites and single pages, and Majestic's Topical Trust Flow covers pages, subdomains and root domains. When you compare your article with its neighbours in the top results, a page-level metric is the fairer one: strong domains have pages with no external links at all.
For your own site, the metrics are most useful as a time series. An absolute DR or IKS says little; the change over a quarter, set next to traffic and the number of linking domains, shows whether your link strategy is working.
Vetting a link source without being fooled by a number
Link marketplaces sell placements by DR or IKS, which is exactly why those numbers get inflated there. This check takes a few minutes per site:
- Compare IKS with DR. A big gap in DR's favour with an empty IKS needs an explanation.
- Look at Citation Flow and Trust Flow, or better, Topical Trust Flow: is the site's subject close to yours?
- Open the site's organic traffic in any tool and look at the trend. A recent sharp drop often means a penalty.
- See who the site links to. Hundreds of outbound links to unrelated commercial sites from every article mean the weight is split among all of them.
- Open a couple of pages yourself. If there is nothing worth reading, no number will fix that.
If you have no link budget at all, start with your own profile: broken links pointing at deleted pages, mentions with no link. That has its own article: working a backlink profile with nothing to spend.
Frequently asked questions
Which authority metric is the most accurate?
None of them. They measure different things: IKS rates a site from Yandex's data about users, DR and Trust Flow describe links in Ahrefs' and Majestic's indexes, and Authority Score adds a traffic estimate to links. You get the clearest picture by reading them together.
Does IKS affect rankings in Yandex?
Yandex's help does not say so. It describes IKS as a measure of how useful a site is to users, recalculated regularly. It is more sensible to treat it as a reflection of the site's state.
Why does a site have a high DR but a low IKS?
DR is calculated from links only; IKS from audience and user behaviour in Yandex. A site with many links and little Yandex traffic gets exactly that combination. Sometimes the links were bought; sometimes the site simply targets Google.
Which should I check before buying a link: DR or Trust Flow?
Both, plus the site's traffic. DR shows profile strength, the gap between Trust Flow and Citation Flow helps you spot manipulation, and Topical Trust Flow shows the subject area.
Can these metrics be raised quickly?
DR and Citation Flow go up with links, bad ones included, which is why they get gamed. IKS depends on audience, and Yandex may zero it for attempts to influence it. All of them rise together and stay up only with real traffic and links from live sites.
Why is a Russian site's Authority Score lower than expected?
Authority Score includes an organic traffic estimate from Semrush's database, which is built on Google data. If most of the site's traffic comes from Yandex, that component is understated.