The Difference Between Domain Rating, Domain Authority, and Trust Flow

Domain Rating, Domain Authority, and Trust Flow are the three most commonly cited 'authority' metrics in SEO and link building — and one of the most persistent sources of confusion in the industry. All three claim to measure something like a website's overall link-based authority on a 0–100 scale. All three are calculated using entirely different proprietary methodologies by three different companies. And crucially, none of them are Google metrics — Google has never published, endorsed, or confirmed using any of these scores, despite how frequently they're treated as if they were.

This guide explains exactly what each metric measures, how they differ, why a site can have a DR of 45 and a DA of 30 for the same domain, and what these scores are actually useful for when used correctly in a link building context.

Domain Rating (DR) — Ahrefs

Domain Rating is Ahrefs' proprietary metric, calculated based on the quantity and quality of unique referring domains pointing to a website, using a logarithmic scale from 0 to 100. DR is calculated similarly in concept to Google's original PageRank algorithm — it evaluates the link graph of referring domains and how authoritative those referring domains themselves are, based on Ahrefs' own crawl of the web.

DR has become the most widely used authority metric in the link building and guest posting industry specifically, largely because Ahrefs maintains one of the largest and most frequently updated backlink indexes available, making DR a reasonably reliable proxy for relative comparison between sites — provided you're comparing DR scores generated from the same Ahrefs index update period, since the underlying index changes over time.

Domain Authority (DA) — Moz

Domain Authority is Moz's proprietary metric, also on a 0–100 logarithmic scale, calculated using a machine learning model trained to predict how well a domain is likely to rank in Google's search results, based on dozens of ranking factors that Moz's index tracks — not solely link-based factors, though link profile data is a significant component.

DA was historically the most widely cited authority metric in SEO, predating Ahrefs' rise to prominence, and remains in wide use today — though many practitioners now consider DR a more directly comparable, link-focused metric, while treating DA as a broader (and somewhat more opaque) composite score that blends multiple signal types into a single number.

Trust Flow (and Citation Flow) — Majestic

Majestic's metrics work differently from DR and DA in a meaningful way: Trust Flow and Citation Flow are presented as a pair, not a single score. Citation Flow measures the raw quantity of links pointing to a domain, regardless of their quality. Trust Flow measures the quality of those links, calculated based on their proximity (in link distance) to a curated seed set of known, trusted websites that Majestic uses as reference points.

The relationship between Trust Flow and Citation Flow is itself diagnostically useful in a way that a single composite score isn't: a domain with high Citation Flow but low Trust Flow (lots of links, but from low-quality or untrustworthy sources) looks meaningfully different from a domain where both scores are high and roughly proportional (a genuinely high-quality, trusted link profile). This TF:CF ratio is a distinctive analytical tool that DR and DA, as single composite numbers, don't directly offer.

Why the Same Domain Shows Different Scores Across Tools

Metric	Provider	Primary basis
Domain Rating (DR)	Ahrefs	Referring domain quantity and quality, based on Ahrefs' own crawl index
Domain Authority (DA)	Moz	Machine learning model predicting Google ranking likelihood, multiple signal types
Trust Flow / Citation Flow	Majestic	Link proximity to a curated trusted seed set (Trust Flow) vs raw link volume (Citation Flow)

Because each company crawls the web independently, maintains a different-sized and differently-updated index, and applies a different proprietary algorithm, the same domain will almost always show different scores across all three tools — sometimes significantly different. This is expected and does not indicate an error in any individual tool; it reflects genuinely different methodologies measuring related but distinct concepts, all under the loosely shared label of 'authority'.

The Critical Point: None of These Are Google Metrics

This is the single most important thing to understand about all three scores: Google does not use Domain Rating, Domain Authority, or Trust Flow in its ranking algorithm. Google has never confirmed using any third-party authority metric, and Google representatives have specifically and repeatedly stated that Domain Authority in particular is not a metric Google uses or recognises.

These metrics are valuable as relative comparison tools built by SEO tool companies to help practitioners estimate authority and prioritise link building targets — they are proxies, calculated independently of Google, that correlate reasonably well with actual ranking performance in aggregate analysis, but they are not the mechanism by which Google actually evaluates a site. A site can have a high DR and rank poorly; a site can have a modest DR and rank exceptionally well, if its actual content quality and the specific relevance of its real link profile (as Google itself evaluates it, using signals not fully visible to any third-party tool) are strong.

The practical implication for link building: use DR, DA, or Trust Flow as a screening and prioritisation tool to compare relative authority between potential link targets — they're genuinely useful for that purpose. Don't treat any of them as a direct proxy for how Google will actually evaluate a specific link, and never optimise a campaign purely to hit a target DR/DA number without regard for the actual quality, relevance, and traffic of the underlying site.

Which Metric Should You Actually Use?

For most link building and guest posting decision-making, Domain Rating has become the de facto industry standard — most publisher rate cards, marketplace listings, and outreach pitches reference DR specifically, largely reflecting Ahrefs' dominant position in the SEO tool market. This makes DR the most practically useful metric simply because it's the one most consistently available and referenced across the publisher ecosystem you'll be evaluating.

That said, the most rigorous approach to evaluating a potential link placement doesn't rely on any single authority score in isolation. Combine the authority metric (DR, as the most widely available reference point) with actual organic traffic data (the strongest single indicator that a site has a real audience, not just an impressive link profile), traffic geography (relevant to your target market), and a manual quality check of the site's actual content and editorial standards. A site with DR 45 and genuine, relevant organic traffic is a better link target than a site with DR 60 and minimal real traffic — regardless of which authority score you're using as your primary reference.

LinksPulse shows DR, traffic, and niche data transparently for every publisher — browse linkspulse.com

FAQ

Q: Why does a site have a high DR but low DA, or vice versa?

Because DR and DA are calculated using entirely different methodologies by different companies with different web crawl indexes. DR is based specifically on Ahrefs' assessment of referring domain quantity and quality from its own index. DA is based on Moz's machine learning model incorporating multiple ranking-related signals, not purely link-based ones. A discrepancy between the two scores for the same site is normal and doesn't indicate an error — it reflects the different things each metric is actually measuring.

Q: Is Domain Rating the same thing as Google PageRank?

No, though they're conceptually related. PageRank is Google's original algorithm for measuring link-based authority, and Ahrefs designed DR to work on a similar conceptual principle (assessing the quality and quantity of incoming links). However, DR is Ahrefs' own independent calculation based on Ahrefs' own crawl data — it is not Google's PageRank, and Google stopped publicly displaying PageRank scores years ago. DR is best understood as Ahrefs' own authority estimate, inspired by similar principles to PageRank but entirely separate from it.

Q: Should I pay more for a link from a higher DR site?

Generally yes, but DR alone shouldn't be the sole pricing justification — a DR 50 site with strong organic traffic and genuine topical relevance to your niche is a better and often fairly-priced investment than a DR 65 site with minimal real traffic or no topical relevance to what you're promoting. Use DR as one input among several (alongside traffic, relevance, and editorial quality) when evaluating whether a given price for a placement represents good value.

Q: Why doesn't Google just publish its own official authority score?

Google has specifically avoided publishing a single authority score, partly because doing so would create an obvious, gameable target for manipulation — exactly the dynamic that occurred historically when PageRank scores were publicly visible in the Google Toolbar (discontinued in 2016 partly for this reason). Google's actual ranking systems use hundreds of signals in combination, and collapsing that into a single public 'authority number' would oversimplify the actual system and invite exactly the kind of gaming behaviour third-party metrics like DR sometimes inadvertently encourage.

Q: Does LinksPulse use DR, DA, or Trust Flow to describe its publisher inventory?

LinksPulse displays Domain Rating (DR) as the primary authority metric for every publisher in the marketplace, reflecting its position as the most widely recognised and consistently available metric across the publisher ecosystem. Alongside DR, every listing also shows actual organic traffic and niche category — giving you the fuller picture this article recommends rather than relying on a single authority score in isolation.