Domain Authority

What Is Domain Authority?

Domain Authority (DA) is a proprietary metric developed by Moz that scores a website's overall ranking potential on a logarithmic scale from 1 to 100. Higher scores indicate greater predicted ability to rank in search results across topics. The score is calculated based primarily on the quantity and quality of backlinks pointing to the domain — specifically the number of unique referring domains and the authority of those linking sites.

It is important to be precise about what Domain Authority is not. It is not a Google metric, not a direct input into Google's ranking algorithm, and not an official measure of anything Google uses. Google has its own internal link authority system, historically called PageRank, which is not publicly exposed. DA is a third-party proxy — a useful competitive benchmark, but not a ground truth. Ahrefs has a parallel metric called Domain Rating (DR); Semrush has Authority Score. All three measure similar underlying link signals and correlate strongly with actual ranking performance.

Domain Authority is also logarithmic, which means the jump from DA 20 to DA 30 is far easier than the jump from DA 60 to DA 70. Most new sites start around DA 1–10. Well-established mid-sized brands typically reach DA 40–60. Major publications and platforms (The New York Times, Wikipedia, Amazon) are DA 90+. The score is relative — what matters is your DA relative to competitors in your niche, not the absolute number.

Why Domain Authority Matters for Marketers

Domain Authority functions as a competitive benchmark for link equity. When evaluating whether a site can realistically compete for a keyword, comparing DA against the domains currently ranking for that keyword tells you the scale of authority investment needed. A DA 25 site targeting a keyword where all top results come from DA 60+ domains faces a structural disadvantage that content quality alone won't overcome.

DA also informs outreach strategy. A link from a DA 70 site transfers substantially more ranking benefit than a link from a DA 20 site. Prioritizing link acquisition from high-DA, topically relevant domains is the most efficient path to improving your own authority and rankings.

However, DA can be gamed and should not be the sole focus of a link building program. Buying links inflates DA temporarily but creates penalty risk. The goal is not a higher DA number — it's a more authoritative backlink profile, which DA happens to reflect when built authentically.

How to Implement Domain Authority Growth

1. Earn high-quality backlinks: The only legitimate path to higher DA is acquiring links from high-authority domains. Prioritize editorial coverage, original research citations, and industry directory listings from credible sources.
2. Topical link relevance: Links from sites relevant to your industry carry more value than equivalent links from unrelated domains. A DA 50 marketing blog linking to your marketing SaaS is worth more than a DA 60 home improvement site linking to the same page.
3. Disavow toxic links: Low-quality, spammy, or purchased links from link farms can suppress your DA and risk manual penalties. Audit your backlink profile annually and disavow obvious toxic links via Google Search Console.
4. Build internal authority architecture: Strong internal linking passes link equity from high-authority pages to strategically important pages. Don't let authority pool in your homepage — distribute it to key category and product pages.
5. Track referring domain growth: Set monthly targets for new referring domains. Consistent growth of 10–20 new unique linking domains per month is a healthy pace for an active link building program.

How to Measure Domain Authority

Check DA in Moz's Link Explorer, Moz Bar (browser extension), or Semrush (which uses its own Authority Score). Compare your DA against direct competitors in your niche — not against industry-leading platforms where the comparison is meaningless.

Track DA monthly alongside referring domain count and Domain Rating (Ahrefs). A rising DA with consistent new referring domain acquisition indicates a healthy link building program. A stagnant or declining DA despite active outreach typically signals that the links being acquired are of insufficient quality.

Domain Authority and AI Search

Domain Authority serves as a proxy for how broadly a site is referenced across the web — and broad, authoritative reference is exactly what increases a brand's presence in AI training data and retrieval systems. Sites with high DA have been linked to by many high-authority sources, which means their content appears in more crawled contexts and is more likely to have been incorporated into AI training corpora. When ChatGPT or Perplexity retrieves sources to synthesize an answer, high-DA content is disproportionately represented — both because it tends to rank higher in the search indices AI systems query and because it appears more frequently in the web data AI models are trained on.