Full Definition
Domain Authority (DA) was invented by the SEO software company Moz as a way to estimate the overall ranking strength of an entire website. The score runs from 1 to 100 — new sites typically start around 1, while giants like Wikipedia or BBC sit above 90. DA is calculated mainly from the number and quality of backlinks pointing to your domain. More trusted, diverse, and relevant inbound links push your score up. But here's the critical nuance business owners often miss: DA is not a Google metric. Google does not use DA in its algorithm. It is a third-party proxy — a useful shorthand for comparing yourself to competitors, not an official ranking factor. Similar scores exist from other tools: Ahrefs calls theirs Domain Rating (DR), Semrush calls it Authority Score. They measure the same concept but use different calculations, so the numbers differ across tools. DA is most useful for evaluating whether a backlink opportunity is worth pursuing. If a site linking to you has DA 60 and you're at DA 20, that link will carry meaningful weight. A link from a DA 5 blog probably won't move the needle. Actionable tip: Don't obsess over your DA number in isolation. What matters more is whether your DA is higher or lower than the top competitors in your local market. If you're at DA 22 and your local rivals are at DA 18–20, you're already in a strong position.