Domain Authority is a score that predicts how well a website will rank in search results

Domain Authority (DA) is a number from 1 to 100 that SEO tools use to estimate how likely a website is to rank high on Google. It is not a Google metric — Google does not publish Domain Authority scores. Instead, companies like Moz created it by studying which websites actually rank well, then building a formula to predict ranking strength based on the links pointing to a site.

The score works like a credit rating for websites. A site with a DA of 70 will typically outrank a site with a DA of 30, all else being equal. But "all else being equal" is the catch — a high DA helps, but it does not may provide rankings. A page's actual content, how well it matches what someone searched for, and how many relevant links point to that specific page matter just as much or more.

Domain Authority is useful for one specific task: comparing two websites to see which one has built more ranking power over time. It is not useful for predicting whether your own site will rank for a particular search term, and it should not be the only metric you watch.

Key Takeaways

  • Domain Authority ranges from 1 to 100 and is calculated by SEO tools, not by Google itself.
  • A higher DA usually means a website has more backlinks from other trusted sites, which helps it rank better overall.
  • DA is relative — it only tells you how one site compares to another, not whether it will rank for your specific search term.
  • Moz's Domain Authority and Ahrefs' Domain Rating are the two most widely used versions, and they use different formulas so the numbers will not match.

How Domain Authority gets calculated

Domain Authority is built on one core idea: websites that have many links from other websites tend to rank higher. The formula looks at the quantity of backlinks (links from other sites pointing to yours), the quality of those backlinks (whether they come from trusted sites or spam sites), and how those links are distributed across the pages on your site.

Moz, which created the original Domain Authority metric, updates its formula regularly. The current version uses machine learning to predict Google rankings based on hundreds of ranking factors, but backlinks remain the dominant signal. A site with 500 links from news outlets and universities will have a much higher DA than a site with 500 links from comment sections and forum spam.

The score is logarithmic, which means the jump from DA 20 to DA 30 is much easier than the jump from DA 70 to DA 80. This reflects reality — it is relatively easy to build some ranking power, but extremely hard to become a top-tier authority site.

Why Domain Authority matters for your own site

If you are building a website and want it to rank in search results, your site's Domain Authority matters because it affects how much ranking power your pages inherit just by being on your domain. A new page on a DA 60 site has a better starting position than a new page on a DA 10 site, even if both pages are about the same topic and have the same on-page content.

This is why people sometimes buy older websites or domains — they are paying for the accumulated backlinks and ranking history, which show up as a higher DA. A domain that has been around for 15 years and has 200 quality backlinks will outrank a brand-new domain in many cases, even if the new domain has better content.

However, DA is not the only thing that matters. A page on a high-DA site can still fail to rank if the content is thin, outdated, or does not match what people are searching for. Conversely, a page on a low-DA site can rank well if it is the most relevant and useful result for that particular search.

Domain Authority versus Page Authority and other metrics

Page Authority (PA) is similar to Domain Authority but measures a single page instead of an entire website. A page can have a higher PA than the domain's DA if that page has attracted many backlinks. For example, a viral blog post might have PA 45 while the whole site has DA 25.

Other companies have created their own versions of this metric. Ahrefs calls theirs Domain Rating (DR), and SEMrush calls theirs Authority Score. They all measure roughly the same thing — backlink strength — but use different formulas, so a site might be DA 50 on Moz but DR 45 on Ahrefs. Do not assume the numbers are interchangeable.

Google itself does not publish a Domain Authority score. Google uses its own internal metrics, including a concept called E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness), but these are not numbers you can look up. Domain Authority is a third-party estimate, useful for competitive research but not a direct measure of how Google sees your site.

How to check your site's Domain Authority

You can check Domain Authority using Moz's free toolbar or by visiting Moz's Link Explorer tool. Type in your domain name, and it will show your DA along with other metrics like the number of backlinks and referring domains. Ahrefs offers a free Domain Rating lookup on their website as well.

Most SEO tools that cost money — including Moz Pro, Ahrefs, and SEMrush — show Domain Authority or its equivalent for any site you look up. If you are just starting out and do not want to pay, the free tools are enough to see where your site stands relative to competitors.

Check your DA every few months rather than every week. Domain Authority updates are not instant — Moz typically refreshes its data every few months — so watching it daily will not tell you anything useful. Focus instead on building quality backlinks and creating content that people actually want to link to.

What actually moves Domain Authority up

Domain Authority increases when other websites link to yours, especially when those sites are themselves high-authority. A single link from a major news outlet or university can move your DA more than 50 links from small blogs. This is why people focus on "link building" — the practice of getting other sites to link to yours.

The most natural way to build backlinks is to create something worth linking to: original research, a tool people find useful, or content that solves a problem better than anything else online. You can also reach out to relevant websites and ask them to link to you, though this works best when you have a genuine reason (you mentioned them, you have new data they would care about, etc.).

Buying links or using link schemes violates Google's guidelines and can actually hurt your rankings. If Google detects that you bought links, it may penalize your site or ignore those links entirely. Building DA the right way takes time, but it is the only approach that does not risk your rankings.

Domain Authority and competitive research

Domain Authority is most useful when you are researching competitors. If you want to rank for a particular search term, look at the DA of the sites that currently rank in the top 10. If they all have DA 50 or higher and your site has DA 15, you know you have a lot of work to do before you can realistically compete for that term.

This does not mean you should give up on competitive terms. It means you should either build your DA first by getting backlinks in your industry, or target less competitive search terms where the ranking sites have lower DA. Many successful websites started by ranking for long-tail, less competitive searches, then built authority over time.

You can also use DA to evaluate whether a site is worth reaching out to for a backlink. A link from a DA 40 site is worth more than a link from a DA 5 site. If you are pitching your content to other websites, prioritize those with higher DA in your industry.

Frequently Asked Questions

Is Domain Authority the same as Google's ranking algorithm?

No. Domain Authority is an estimate created by SEO tools based on backlinks and other public data. Google uses its own internal algorithm that includes hundreds of factors. DA is useful for competitive research but does not directly reflect how Google ranks your site.

Can I improve my Domain Authority quickly?

No. Domain Authority updates every few months and reflects the backlinks you have accumulated over time. There is no shortcut. Building DA requires getting links from other websites, which takes months or years of consistent effort.

Does a high Domain Authority may provide I will rank for my target keywords?

No. A high DA gives you an advantage, but rankings depend on many factors including content quality, relevance to the search term, user experience, and the specific backlinks pointing to that page. A high-DA site with poor content can still rank below a low-DA site with better content.

Should I buy an old domain just for its Domain Authority?

Only if the domain's backlinks are relevant to your industry and the content history will not hurt you. Buying a domain with high DA but a history of spam or unrelated content can actually harm your rankings. Make sure the domain's backlink profile matches what you plan to do with it.

Why do Moz and Ahrefs show different Domain Authority scores for the same site?

They use different formulas and different backlink databases. Moz's Domain Authority and Ahrefs' Domain Rating both measure backlink strength but calculate it differently, so the numbers will not match. Use one tool consistently rather than comparing across tools.