Definition
Domain Authority is a score from 1 to 100, created by the SEO software company Moz, that predicts how likely a website is to rank in search results. Higher means stronger. It’s built from a machine-learning model trained on Moz’s own web index, and it draws mainly on a site’s backlink profile — how many unique domains link to it, how many links total, and how trustworthy those linking sites are. A brand-new site starts near 1; established names like Wikipedia sit in the 90s.
Disambiguation — this is the part people get wrong most often: Domain Authority is not a Google ranking factor. Google doesn’t read it, doesn’t use it, and has said so repeatedly — Gary Illyes and John Mueller have both stated over the years that Google holds no overall “domain authority” metric of the Moz kind. DA is a third-party approximation, a thermometer that reports temperature without creating the heat. It correlates with rankings because DA and Google both lean heavily on backlinks, so the same strong link profile that lifts your DA also happens to be what Google rewards. The correlation comes from the shared input, not from Google looking at the score. (The 2024 Google Search API documentation leak did reveal an internal siteAuthority signal — but that’s Google’s own system, not Moz’s DA.)
A second point of confusion: DA is one of several competing vendor scores, and they aren’t interchangeable. Moz calls its metric Domain Authority. Ahrefs calls its version Domain Rating (DR). Semrush calls its version Authority Score. Each uses different data and different math, so a site’s DA and DR won’t match. If someone quotes “a score of 50,” the first question is always: from which tool?
Why it matters for marketing
DA earns its place not because it’s accurate in any absolute sense, but because the industry treats it as a shared shorthand. It’s the most commonly referenced third-party SEO metric, which makes it useful for three practical jobs: sizing up competitors, judging whether a backlink opportunity is worth pursuing, and reporting link-building progress to clients or leadership in a single number they’ll remember.
The trap is chasing the number itself. DA is comparative and logarithmic, so moving from 20 to 30 is a season’s work while 70 to 80 can take years, and a high DA on a site with no traffic and no brand searches signals very little. Treat it the way you’d treat a fellow technical-SEO indicator like Core Web Vitals — a directional gauge that supports strategy, not a target you optimize for directly. The authority DA tries to approximate also increasingly feeds visibility in generative search: site-level trust shapes which sources get cited in AI Overviews, even though the Moz score itself plays no part in that.
See also: Core Web Vitals (CWV) · AI Overviews · Citation Optimization
How it’s calculated
Moz doesn’t publish the exact formula, but the inputs are well documented. The model evaluates dozens of factors, with the heaviest weight on the link profile: the count of linking root domains, the total number of links, and the quality of the sites doing the linking. It then predicts how often a domain is likely to appear in Google’s search results relative to other domains, and expresses that as a 1-to-100 score.
Two mechanics matter in practice:
- It’s relative and logarithmic. Every score is judged against the whole range of sites in Moz’s index. Because the top of the scale is crowded with heavily linked domains, each additional point gets harder to earn as you climb. Your own SEO can improve without your DA moving, if the sites around you improved too.
- It’s recalculated on Moz’s cycle, not yours. Moz refreshes DA roughly once a month as its crawler finds and loses links. A great new link might not show up for weeks, and your score can dip if a high-authority domain simply drops out of Moz’s index — even when your content and your Google rankings haven’t changed at all.
One detail trips up newcomers constantly: 100 links from a single site still count as one linking root domain. Diversity of sources beats raw link volume.
How to utilize Domain Authority
Check it free through Moz’s Link Explorer or the MozBar browser extension, which shows DA in the search results as you browse. Then use it comparatively.
- Competitive benchmarking. Pull the DA of the sites actually ranking for your target keywords. If your top three competitors sit at 22, 25, and 31, a DA of 28 means you’re in the fight and there’s no fire to put out. If they’re at 45, 52, and 58, the gap is real and worth a plan. Benchmark against your SERP, never against the abstract scale.
- Link prospecting. DA helps you weigh potential backlink sources, but relevance and real referral traffic matter more than the number. A topically relevant link from a modest site can beat a high-DA link from an unrelated one.
- Progress reporting. Because it’s a single, familiar figure, DA is a convenient way to show link-building momentum over quarters — with the caveat that it moves slowly and on Moz’s schedule.
Comparison: DA vs. other authority scores
| Metric | Vendor | Scale | Primary inputs | A Google ranking factor? |
|---|---|---|---|---|
| Domain Authority (DA) | Moz | 1–100 (logarithmic) | Linking root domains, total links, link quality | No |
| Domain Rating (DR) | Ahrefs | 0–100 (logarithmic) | Backlink profile strength / linking domains | No |
| Authority Score | Semrush | 0–100 | Link power, organic traffic, spam signals | No |
| Page Authority (PA) | Moz | 1–100 | Same model as DA, applied to a single page | No |
None of these is used by Google in its ranking algorithm. The scores are not directly convertible between tools — different data sets and methods produce different numbers for the same site. See editorial note on cross-tool conversion.
Best practices
- Build what the number measures, not the number. Earn relevant, high-quality backlinks; publish content worth linking to; keep the technical foundation sound. DA rises as a side effect of doing the real work.
- Diversify linking domains. Since a root domain counts once regardless of how many links it sends, breadth of referring sites moves DA more than piling links from the same few places.
- Prioritize links that send traffic. A link that brings engaged referral visitors signals genuine relevance — which is closer to what Google actually rewards than any authority score.
- Compare against competitors, not the scale. “Good” is entirely relative to your niche. DA 35 can be strong for a local service business and weak for a national SaaS brand.
- Prune genuinely toxic links, but don’t expect miracles. Removing spammy or manipulative links protects against drag; it rarely produces gains on its own. New quality links do the lifting.
- Don’t time audits around Moz’s update. The cycle is monthly and outside your control. Track your rate of referring-domain growth instead of watching for the score to twitch.
Future trends
The clearest shift is that pure link-based authority scores are losing standing as a proxy for real influence. Google’s own systems increasingly reward brand demand — navigational searches for your name that mark you as a real entity — and can spot high-DA “zombie” domains that carry a big score but no traffic or trust. Expect the industry to keep pairing DA with engagement and brand-search signals rather than reading it alone.
The generative-search angle sharpens this. Answer engines and large language models tend to cite domains with established credibility and topical depth, so the link-building and content work that grows DA is broadly the same work that positions a brand for AI answer attribution and stronger Citation Optimization. The Moz score won’t be the thing machines read — but the underlying authority it approximates matters more, not less, as discovery moves into AI surfaces.
FAQs
Is Domain Authority a Google ranking factor? No. DA is a Moz metric, and Google doesn’t use it. Google reps have denied any Moz-style domain authority metric for years. DA correlates with rankings only because both rely on backlinks.
What’s a good Domain Authority score? There’s no universal answer — it’s relative to your industry and competitors. Benchmark against the sites ranking for your target keywords rather than chasing a fixed number. As a rough directional guide, above 60 is generally considered strong, but context decides.
How is Domain Authority calculated? Moz uses a machine-learning model, weighted mainly toward the backlink profile — linking root domains, total links, and link quality — to predict how likely a domain is to appear in Google’s results. The exact formula is proprietary.
Why did my DA drop when I didn’t change anything? Because DA is relative and recalculated on Moz’s cycle. Competitors gaining links, a linking site dropping out of Moz’s index, or a Moz algorithm update can all move your score without any change on your end.
How is DA different from Domain Rating (DR) and Authority Score? They’re separate metrics from separate tools — DA is Moz, DR is Ahrefs, Authority Score is Semrush. All estimate backlink strength, but with different data and math, so the numbers don’t match and aren’t directly convertible.
What’s the difference between Domain Authority and Page Authority? DA scores an entire domain or subdomain; Page Authority (PA) applies a similar model to a single page. A strong domain can still have weak individual pages if those pages lack their own inbound links.
How long does it take to increase DA? Typically months of consistent link earning and content work — often six to twelve. The scale is logarithmic, so gains slow markedly as your score climbs.
Does Domain Authority affect AI Overviews or LLM citations? Not the Moz score itself. But the site-level authority and topical depth that produce a high DA do influence which sources generative systems cite, so the underlying work carries over.
How do I check my Domain Authority for free? Use Moz’s Link Explorer or the MozBar extension. Semrush and other platforms show DA via their own extensions too, drawn from Moz’s data.
Related Terms
- Core Web Vitals (CWV)
- AI Overviews
- Citation Optimization
- Page Authority (PA)
- Domain Rating (DR)
- Authority Score
- Backlink
- PageRank
- MozRank
- E-E-A-T
Sources
- Moz — Domain Authority (official documentation): https://moz.com/learn/seo/domain-authority
- Moz — Page Authority (official documentation): https://moz.com/learn/seo/page-authority
- Google Search Central — Ranking results / how Search works: https://developers.google.com/search/docs/fundamentals/how-search-works