What is Domain Authority?
Domain authority is a concept (and a Moz metric scored 0-100) representing the overall strength of a website's backlink profile and its likelihood of ranking in search results — used as a comparative measure of competitive strength between websites.
Why It Matters
Every SEO conversation eventually comes to authority. "Can we rank for this keyword?" depends largely on whether the site has enough authority to compete. Domain authority provides a quick, comparative answer. A site with DA 40 will struggle to rank for keywords dominated by sites with DA 70+. A site with DA 60 has a realistic chance of competing for moderately competitive terms.
Domain authority is not a Google ranking factor — it is a third-party metric created by Moz. Google has its own internal authority measures that it does not share publicly. But DA (and Ahrefs' Domain Rating, its equivalent) correlates strongly with ranking ability because both measure the same underlying signal: backlink profile strength. DA serves as a practical proxy for competitive analysis and goal setting.
How It Works
Domain authority is calculated from backlink data:
- Link quantity — The number of unique domains linking to the website. More referring domains generally means higher authority, though quality filters apply.
- Link quality — The authority of the linking domains themselves. Links from high-DA sites contribute more than links from low-DA sites. Authority flows through the link graph.
- Logarithmic scale — DA is scored 0-100 on a logarithmic scale. Moving from DA 20 to 30 is relatively easy. Moving from 60 to 70 is significantly harder. Moving from 80 to 90 is extremely difficult. Each point higher requires exponentially more backlink strength.
- Relative scoring — DA is comparative. It is most useful for comparing your site against competitors and tracking directional progress over time, not as an absolute measure of quality.
Common Mistakes
Treating domain authority as a goal to optimise for directly. DA is a lagging indicator of backlink strength — it reflects the result of link building, not a target to chase. Tactics that inflate DA without building genuine authority (link exchanges, PBNs, directory spam) may increase the number but do not improve actual ranking ability.
The other mistake is comparing DA across different industries. A DA 30 site in a niche B2B market may dominate its SERPs, while a DA 30 site in travel or finance cannot compete for any meaningful keyword. DA must be evaluated relative to the competition for your specific keywords, not against arbitrary benchmarks.
How I Use This
My advanced SEO audit uses domain authority (and domain rating) as part of competitive gap analysis. The audit compares your authority metrics against the sites currently ranking for your target keywords, identifying whether the gap is addressable with content and on-page improvements or whether significant link building is needed to compete.
References & Authority
This term is recognised by established knowledge bases:
Related Services
How BrightIQ uses Domain Authority
This concept is central to the following services:
Related Terms
Backlink
A backlink is a link from another website to yours — functioning as a vote of confidence that tells search engines the linked content is valuable, trustworthy, and worth ranking. Backlinks remain one of Google's most important ranking factors.
Domain Rating
Domain rating (DR) is a metric developed by Ahrefs that scores a website's backlink profile strength on a scale of 0-100 — measuring the quantity and quality of external links pointing to the domain as a proxy for its ability to rank in search results.
Link Building
Link building is the practice of acquiring hyperlinks from other websites to your own — through outreach, content creation, digital PR, and relationship building — to increase domain authority and improve search rankings.
Off-Page SEO
Off-page SEO covers every optimisation action taken outside of your own website to influence search rankings — link building, brand mentions, digital PR, social signals, and entity associations that signal authority and trust to search engines.