DA, DR, PA & Trust Flow: What Each Metric Measures

Ask five SEOs which authority metric matters most and you'll likely get five different answers — and that's a reasonable outcome, because none of these scores come from Google. Domain Authority, Domain Rating, Page Authority, and Majestic's Trust Flow and Citation Flow are all third-party estimates, each built from a different company's crawl of the web. Understanding what each one actually measures — and what it doesn't — keeps you from making link decisions based on a number that was never designed to predict rankings on its own.

Domain Authority (Moz)

Domain Authority, or DA, is Moz's score from 1 to 100 predicting how likely a domain is to rank well in search results, based primarily on the quantity and quality of backlinks pointing to it. It's a logarithmic scale, meaning the jump from 20 to 30 is far easier than the jump from 70 to 80 — a detail that trips up a lot of comparisons between sites at different authority tiers.

DA is built entirely from Moz's own Link Explorer index. It does not factor in Google's actual ranking algorithm, traffic, or content quality — it's a correlation-based estimate, and Moz itself describes it as a comparative tool rather than an absolute measure of SEO health.

Domain Rating (Ahrefs)

Domain Rating, or DR, serves a similar purpose but comes from Ahrefs' independent link index. DR measures the strength of a domain's overall backlink profile on a 0–100 scale, largely focused on the quantity and quality of referring domains rather than individual backlinks.

Because Ahrefs and Moz crawl different portions of the web and weight links differently, DA and DR scores for the same domain frequently diverge — sometimes significantly. Neither is "more correct"; they're simply different models built on different data.

Page Authority (Moz)

Page Authority, or PA, is Moz's equivalent metric at the individual page level rather than the whole domain. A domain can have a high DA while a specific page on it has a low PA, if that particular page has few links pointing directly to it. This distinction matters for guest posting and placement decisions: the domain's overall authority doesn't guarantee that a specific article page carries much weight — what you're actually borrowing equity from is the page, not just the brand.

Trust Flow and Citation Flow (Majestic)

Majestic takes a different angle entirely. Citation Flow (CF) measures the quantity of links pointing to a site, while Trust Flow (TF) measures their quality, based on how closely a site's links trace back to a curated set of known trustworthy seed sites. The ratio between TF and CF is often more informative than either number alone: a site with high Citation Flow but low Trust Flow typically has a large volume of low-quality or spammy links, while a balanced or TF-leaning ratio suggests a cleaner, more trustworthy link profile.

Why none of these predict rankings directly

It's worth repeating plainly: Google has stated clearly and repeatedly that it does not use DA, DR, PA, TF, or any other third-party metric in its ranking systems. These scores are built by crawling the web independently and modeling what each company believes correlates with ranking well — they are educated proxies, not inputs Google itself consults.

That's not a reason to ignore them. They correlate reasonably well with real authority in aggregate, and they're genuinely useful for quick triage — screening a list of a hundred potential link opportunities down to twenty worth a closer look. The mistake is treating any one score as a precise, authoritative judgment rather than a rough filter.

Why you shouldn't over-index on a single number

A site can have an inflated DA or DR from a burst of low-quality links, a brief viral moment years ago, or tactics specifically designed to game one tool's index — while having negligible real traffic or relevance to your niche. Conversely, a genuinely strong, niche-relevant publisher with a smaller but real, engaged audience might show a modest score simply because it hasn't been around as long or hasn't been crawled as thoroughly.

A more reliable evaluation combines several signals:

• Topical relevance to the page you're trying to rank — often more important than raw authority.
• Real organic traffic, checked independently rather than assumed from the authority score.
• The TF/CF ratio or equivalent, as a sanity check against spammy link volume.
• Consistency across tools — a site that scores reasonably on DA, DR, and TF simultaneously is a safer bet than one with wildly inconsistent numbers.

Marketplaces such as 0backlink that surface verified traffic data alongside these authority scores make this cross-checking faster, since you're not manually running every candidate site through three separate tools before making a decision.

The practical takeaway

DA, DR, PA, and TF/CF each measure a slightly different slice of "authority," built from different data with different assumptions. Used together as a filtering layer — and verified against real relevance and traffic — they're genuinely useful. Used alone as a single pass/fail threshold, they'll just as often mislead you as guide you correctly.