What is domain authority, and how do you check it free?

What is domain authority?

Domain authority is a score that estimates how strong a whole website is in search, based mainly on how many other sites link to it and how strong those sites are. The term comes from Moz, whose Domain Authority (DA) runs from 1 to 100 and, in Moz's words, predicts how likely a website is to rank on search results pages compared with competitors. Higher is stronger.

Over time “domain authority” has become a generic name for the whole family of these scores. When someone asks “what is my domain authority?”, they may mean Moz DA, Ahrefs Domain Rating, Semrush Authority Score or any tool's similar number. They are cousins, not twins: each vendor crawls its own copy of the web and applies its own formula, so the same site can score 35 in one tool and 50 in another.

Three facts about Moz DA from Moz's own Domain Authority guide apply, in spirit, to all of them:

• It is relative. DA compares your site with every other site in Moz's index, so it is most useful for benchmarking against competitors in your own industry.
• It is built from links. Moz calculates DA with a machine learning model over its Link Explorer index; the number of linking root domains and the quality of those links weigh most.
• It moves without you doing anything. Because the scale is relative, Moz explains that if a giant site gained a huge number of new links, other sites' DA would drop, and that growing from 20 to 30 is easier than from 70 to 80.

Does Google use domain authority?

No. Google does not use Moz DA, Ahrefs DR, Semrush Authority Score or any other tool's authority score, and there is no Google domain authority checker. Moz states that Domain Authority “is not a Google ranking factor and has no effect on the SERPs”. Google's own guide to its ranking systems describes link analysis and PageRank as one of its core systems, but names no third-party score.

Links do matter to Google, which is why these scores are useful at all. Google's SEO Starter Guide says PageRank uses links and is one of Google's fundamental algorithms, and adds that there is much more to Google Search than just links. So treat any authority score as a third-party estimate of one input Google cares about, not as a reading from Google.

People searching for a “Google domain authority checker” usually want one of two things: a free authority score (use one of the tools below), or Google's own view of who links to them. For the second, open the Links report in Search Console. It lists your top linking sites, top linked pages and top linking text. Google notes it is a sample, not every link, and it gives no score.

Moz DA vs Ahrefs DR vs Semrush Authority Score

All three estimate site strength from links, but they use different indexes and formulas, and only Semrush's adds traffic and spam signals. The table below sticks to what each vendor says in its own documentation.

The practical consequence: never compare a number from one tool with a number from another. A DR of 40 and a DA of 40 do not describe the same strength. Pick one tool and compare your site with your competitors inside it.

How to check domain authority of a website for free

To check Moz DA free, use Moz Link Explorer with a free Moz account, or install MozBar; to check MrKeyword's score, enter the domain in its free domain authority checker. Here are the steps for each, plus how to read the result.

1. Moz's free domain authority checker: Link Explorer

   Go to Moz Link Explorer, enter the URL, create a free Moz Community account and verify your email. Moz says the free account gives 10 queries a month and shows Domain Authority, Page Authority, Spam Score and inbound link counts. Moz also lists a free Domain Analysis tool on its free tools page.

2. MozBar, for checking DA as you browse

   MozBar is Moz's free browser toolbar. Moz says it shows Domain Authority, backlinks and linking root domains for the page you are on, which is handy for a quick look at the sites ranking for a query.

3. MrKeyword's domain authority checker

   Enter any domain on the MrKeyword domain authority checker, with or without https://, and sign in with a free account. You see MrKeyword Link Authority with its source, a confidence level and an as-of date. It needs no Search Console access, so it works for competitors too. To see who links to the site, use the free backlink checker.

4. Ahrefs and Semrush, if you want their numbers

   Ahrefs runs a free Website Authority Checker that shows Domain Rating. Semrush runs a free Website Authority Checker for Authority Score; its page says no login is needed.

5. Read it against your competitors

   Check the 3–5 sites that rank above you for your main queries in the same tool. Moz says there is no universal “good” DA; what matters is how you compare with the sites you compete with.

What is a good domain authority score?

There is no universal good score; a good domain authority is one close to or above the sites you compete with for the same searches. Moz, Ahrefs and Semrush all say the same thing in their documentation: the number is relative, and it is best used to compare sites rather than judged on its own.

• New sites start low. Moz says new websites always start with a DA of 1 and rise as they earn links.
• Small local businesses usually score low, and that is normal. A plumber does not compete with a national newspaper; it competes with other plumbers in its town.
• The scale is not linear. Moving from 20 to 30 is far easier than moving from 70 to 80, so do not expect steady points per month.

A low score is not a ranking ceiling. Pages on low-authority sites rank every day for specific questions they answer better than anyone else. Our guide on how to increase domain authority covers what actually moves the needle, and why chasing the number is a mistake.

Why do DA checkers show different numbers for the same site?

Each tool crawls a different part of the web and weighs links with a different formula, so their scores never match. Three things drive the differences:

• The index. No tool sees every link. A link one crawler found may be missing from another, and indexes refresh on different schedules.
• The formula. Moz uses a machine learning model trained against rankings, Ahrefs splits a linking site's rating across everything it links to, and Semrush blends links with estimated traffic and spam checks.
• The relative scale. Because each score is relative to everything else in that tool's index, a site's score can change when other sites gain or lose links.

That is why sudden jumps or drops in a third-party score are worth a look in your links, but are not evidence that Google changed its view of your site. For Google's view, look at your clicks and impressions in Search Console.

How MrKeyword's authority score works

MrKeyword Link Authority is MrKeyword's own 0–100 score: a PageRank over the links in its own index plus the MrKeyword web graph, labelled “Derived” wherever it appears. It is comparable in spirit to Moz DA, but it is not Moz DA and the numbers will differ.

• The links. Followed, cross-domain links found by MrKeyword's crawler, plus the domain-to-domain links in MrKeyword's web graph. No backlink data is bought from a third party.
• The formula. A domain-level PageRank with a damping factor of 0.85, scaled 0–100 on a log curve against the strongest domain in the graph.
• Link farms. Domains that look like one-way link hubs or reciprocal link rings are detected, and the links they give are counted at a tenth of normal weight.
• A fallback for any domain. When MrKeyword has seen links from fewer than 10 referring domains, the score comes from the domain's PageRank position in MrKeyword's domain ranks instead, so well-known domains get a number even before MrKeyword's own crawl reaches them. The result says which source was used.
• Confidence. Each score is marked high (50 or more referring domains), medium (10 to 49) or low (under 10), with the date it was computed. A domain with no links in either source shows no score rather than a guess.

What MrKeyword does not do

MrKeyword does not show Moz DA, Ahrefs DR or Semrush Authority Score, and it does not claim to see every link on the web. To be clear about the limits:

• It does not resell or estimate another vendor's metric. If you need Moz DA specifically, for example because a client contract names it, use Moz's own tools.
• Its link index is smaller than the big commercial backlink databases. It covers what MrKeyword's crawler and web graph have seen, and labels the source of each referring domain. The Ahrefs alternative and Semrush alternative pages say plainly where a dedicated link tool is the better choice.
• It does not predict rankings from the score. Link Authority is one input; your Search Console data shows how you actually rank.
• It does not sell links or run outreach. A higher number is earned, not bought.

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