What is domain authority?
Domain authority is a score an SEO tool gives a whole website to estimate how strong its links are. Each tool builds its own. The name comes from Moz (Domain Authority, DA). Ahrefs has Domain Rating (DR) and Semrush has Authority Score.
The tools describe their scores differently:
- Ahrefs says DR "shows the strength of a website's backlink profile compared to the others in our database", on "a 100-point scale" (Ahrefs Help Center, read 1 November 2026).
- Semrush calls Authority Score "our compound metric that grades the overall quality of a website or a webpage". It mixes link power, estimated organic traffic and spam signals, on a scale of 1 to 100 (Semrush Knowledge Base, read 1 November 2026).
- Moz says Domain Authority "is a search engine ranking score developed by Moz" that "predicts how likely a website is to rank" compared to competitors, on a scale of 1 to 100 (Moz, last updated 18 March 2025, read 1 November 2026).
So a DR of 60 and a DA of 60 are not the same number. Compare sites with one tool only.
Does Google use domain authority?
Not as such. These are third-party scores. Moz itself says DA "is not used by Google to determine search engine rankings". Google's guide to its ranking systems lists no domain-wide authority score. It does say PageRank, which reads how pages link to each other, "continues to be part of our core ranking systems" (Google Search Central, last updated 2025-12-10, read 1 November 2026). The tools try to estimate the same kind of link strength from outside.
Ahrefs itself only claims a correlation: "DR correlates with Google rankings pretty well", and it adds that its page-level URL Rating does this better. A correlation is not a cause.
Why does domain authority matter for B2B SaaS?
Brands use it as a quick filter when they pick sites for a guest post or a spot in a list. Publishers put it on their rate cards. It is a quick first check of how many sites link to a domain through backlinks.
It is a weak last check. A high score does not tell you whether the page ranks for the search your buyers use, whether real people visit it, or whether AI assistants cite it. Scores can also be pushed up with link spam.
How to judge a site beyond the score
- Check that the exact page ranks for a search your buyers use.
- Look at real traffic to that page, ideally from the publisher's Search Console.
- Ask an AI assistant the buyer's question and see whether the page is cited.
- Read the page. Is it useful, current and honest about each entry?
- Check how paid links are marked. See nofollow.
Example (hypothetical)
A hypothetical brand picks between two list articles. Site A has a DR of 78 but the list gets no search traffic. Site B has a DR of 41, ranks third for "best help desk for small teams" and is cited by Perplexity for that question. For reaching buyers, site B is the better spot, even with the lower score.
Domain authority and AI citations
AI assistants do not publish an authority score either. Google says AI Overviews and AI Mode have no extra requirements beyond normal SEO (Google Search Central, read 1 November 2026), so strong sites help there. But which page gets cited depends on the question. For the full picture of buying list spots, see listicle placements for B2B SaaS.