Domain authority usually refers to Moz’s Domain Authority (DA), a score from 1 to 100 that predicts how likely a website is to rank, based mainly on its backlinks. Similar metrics include Ahrefs’ Domain Rating (DR) and Semrush’s Authority Score (AS). They are useful yardsticks in off-page SEO, but they are not Google metrics.
How the scores are calculated
- Moz DA: a machine-learning model using linking root domains, link quality and other factors, scaled to correlate with rankings.
- Ahrefs DR: based on the number and strength of unique domains with followed links to the site.
- Semrush AS: combines link data with organic traffic and spam signals.
All are logarithmic, so moving from 20 to 30 is far easier than from 70 to 80.
Does Google use domain authority?
No. Google has repeatedly said it does not use DA, DR or any similar sitewide score. It does use links and many page-level and site-level signals, which these tools try to approximate. Treat the scores as estimates, not targets.
When domain authority is useful
- Comparing your link strength with competitors.
- Quickly judging prospects for outreach or guest posting.
- Tracking whether link building is moving the needle over months.
- Estimating how hard a keyword will be, alongside keyword difficulty.
When it misleads
- Sites can inflate DR with cheap links from link farms while having no real traffic.
- A low-DA site with highly relevant content can outrank high-DA generalists.
- Scores drop when the tool updates its model, even if nothing changed on your site.
Always check a linking site’s real organic traffic and relevance, not just its score.
How to increase domain authority
- Earn links from relevant, respected websites through link building and digital PR.
- Create linkable assets: research, tools, guides.
- Fix broken pages that have backlinks with 301 redirects.
- Reclaim unlinked brand mentions.
- Build a strong internal linking structure so authority reaches key pages.
- Avoid paid link schemes, which can be devalued overnight.
Domain authority vs topical authority
Link-based scores measure broad strength. Topical authority measures depth in a subject. The best results come from both.
Frequently asked questions
What is a good domain authority?
It is relative. Compare with the sites ranking for your keywords, not with Wikipedia.
Why did my DA drop?
Lost links, a model update, or competitors growing faster. Check your referring domains.
Related terms
See backlinks, toxic backlinks and the SEO encyclopedia.
Mr. SEO
Mr. SEO is the webmaster at SEO TT - SEO tips and tricks, a publication about all things SEO related.