What Is Domain Authority, and How Can You Improve It?

Spend any time around SEO tools, domain marketplaces, or link-building pitches and you will see a number from 1 to 100 attached to every website: "DA 45", "high-DA guest posts", "this domain has a DA of 60". Domain Authority has become a kind of shorthand for how strong a website is, and plenty of people assume Google uses it to decide rankings. It does not. Domain Authority is a metric created by the SEO software company Moz to estimate how likely a site is to rank, based mostly on its backlinks. Understanding what it measures, what it does not, and how it compares with similar scores from Ahrefs and Semrush will help you use it sensibly, and avoid paying for things that only move a third-party number. This article covers how Domain Authority works, the main alternatives, how to check it, and the practical steps that improve both the score and, more importantly, your actual search visibility. If you are evaluating a domain to buy, pair this with our guide on how to value a domain name.

What Domain Authority Actually Is

Domain Authority (DA) is a score from 1 to 100 that Moz calculates for every domain in its link index. According to Moz, it predicts how likely a website is to rank in search results relative to other sites. A higher score means Moz's model expects the site to have a better chance of ranking.

Several properties of the score are important:

• It is a Moz metric. Moz invented it, Moz calculates it from Moz's own web crawl, and only Moz tools display it.
• It is comparative, not absolute. A DA of 40 does not mean anything on its own. It is most useful for comparing your site with the specific competitors you face in search results.
• It is logarithmic. Moving from 20 to 30 is much easier than moving from 70 to 80. A handful of very large sites sit near the top of the scale.
• It is driven by links. The model relies heavily on link data: how many unique domains link to you, how strong those domains are, and other link-based signals. Moz relaunched the metric as "Domain Authority 2.0" in 2019 with a machine-learning model trained against real search results.
• It changes when Moz's index changes. Your DA can move even when nothing about your site changed, because Moz recrawls the web and recalibrates the scale.

Moz also publishes Page Authority (PA), the same idea applied to individual URLs, and Spam Score, an estimate of how many features a site shares with sites Moz has seen penalized or banned.

Is Domain Authority a Google Ranking Factor?

No. Google does not use Moz's Domain Authority, and it has no access to how Moz calculates it. Google representatives, including John Mueller, have said publicly and repeatedly that Google does not have a "domain authority" score of the kind SEO tools display.

Where the confusion comes from is that Google does use links as a ranking signal. PageRank, Google's original link analysis algorithm, still exists in evolved form inside Google's systems, although the public PageRank toolbar score was retired years ago. Third-party scores like DA try to approximate the effect of links from the outside, using each vendor's own crawl. So a site with a high DA often ranks well, not because of the DA number, but because the same strong backlinks that raise DA also help it in Google.

That distinction has practical consequences:

If you do this...	DA may change?	Google rankings may change?
Earn links from respected sites in your field	Yes	Yes
Buy links from a network of "high-DA" blogs	Yes	Unlikely, and risky
Submit a disavow file in Search Console	No	Possibly
Publish genuinely useful content that gets no links	No	Yes
Fix technical issues blocking indexing	No	Yes

Moz itself presents DA as a comparative, diagnostic metric rather than something to optimize for directly.

Comparable Metrics From Other Tools

Every major SEO platform has built its own version of the idea. The numbers are not interchangeable, because each tool crawls a different portion of the web and uses a different formula. Always compare like with like.

Metric	Vendor	Scale	What it is based on
Domain Authority (DA)	Moz	1–100	Machine-learning model built mainly on Moz link data, predicting ranking likelihood
Domain Rating (DR)	Ahrefs	0–100	The strength of a site's backlink profile, based on unique referring domains and their own DR, counting followed links
Authority Score (AS)	Semrush	0–100	A compound score that combines link power, organic traffic estimates, and spam-related factors
Trust Flow / Citation Flow	Majestic	0–100	Citation Flow reflects link volume; Trust Flow reflects proximity to a manually reviewed set of trusted sites

A few practical notes:

• Ahrefs DR is the most purely link-based of the group. It does not try to predict rankings; it measures backlink profile strength on a logarithmic scale.
• Semrush Authority Score deliberately mixes in traffic data, so a site with lots of links but almost no organic traffic tends to score lower than its link profile alone would suggest.
• Majestic Trust Flow is useful as a sanity check against Citation Flow. A site with a high Citation Flow but very low Trust Flow often has lots of low-quality links.

When two tools disagree sharply about a domain, that is itself useful information. It usually means one crawler has discovered a block of links the other has not, and those links are worth inspecting.

How to Check Domain Authority

The simplest options are Moz's free Link Explorer (with a free account, subject to query limits) and the MozBar browser extension, which shows DA and PA on search results pages. Most domain marketplaces and many SEO plugins also display it.

For bulk checks, Moz offers an API. The long-standing Links API v2 accepts a list of targets and returns DA, PA, and Spam Score among other fields. Moz has been rolling out newer API versions, so confirm the current endpoint and authentication method in Moz's API documentation before building on it. A request against the v2 endpoint looks like this:

curl -s -u "$MOZ_ACCESS_ID:$MOZ_SECRET_KEY" \
  -X POST https://lsapi.seomoz.com/v2/url_metrics \
  -H 'Content-Type: application/json' \
  -d '{"targets": ["example.com", "competitor-one.com", "competitor-two.com"]}' \
  | jq '.results[] | {page, domain_authority, page_authority, spam_score}'

Run the same comparison every month or quarter and track the gap between you and your competitors, rather than obsessing over your absolute number.

How to Improve Domain Authority (the Right Way)

Because DA is mostly a model of your backlink profile, improving it means earning more links from more distinct, well-regarded websites. The good news is that the work that improves DA is the same work that improves real search performance, as long as you focus on genuinely earning links rather than manufacturing them.

1. Publish Content People Want to Reference

Links follow usefulness. The content that tends to attract links naturally includes:

• Original data and research: surveys, benchmarks, analyses of public datasets.
• Definitive guides and references that others cite instead of explaining a topic themselves.
• Free tools and calculators, which attract links for years.
• Clear explanations of things that are commonly misunderstood in your field.

A single strong reference resource can earn more referring domains than dozens of thin posts.

2. Do Outreach and Digital PR

Great content still needs to be discovered. Share original research with journalists and newsletter writers who cover your niche, offer expert commentary through reporter-request platforms, and present at or sponsor relevant events and communities. Links from news sites, universities, and well-known industry publications carry much more weight than a large number of links from small, unrelated blogs.

3. Reclaim Links You Have Already Earned

This is the fastest win for most established sites. Over time, pages get deleted, URLs change, and site migrations leave old URLs returning 404 errors. Every external link pointing at a broken URL is wasted. Export your linked pages from Google Search Console (Links report, "Top linked pages") or a backlink tool, then check which ones no longer resolve.

This Python script reads a CSV export with a column of URLs and reports any that do not return a 200 status:

#!/usr/bin/env python3
"""Find linked pages that are broken or redirecting.
Usage: python3 find_broken_linked_pages.py top-linked-pages.csv [column_name]
"""
import csv
import sys

import requests


def main(path, column="Target page"):
    session = requests.Session()
    session.headers["User-Agent"] = "link-reclamation-check/1.0"
    with open(path, newline="", encoding="utf-8-sig") as f:
        for row in csv.DictReader(f):
            url = row[column].strip()
            if not url.startswith("http"):
                continue
            try:
                resp = session.get(url, allow_redirects=False, timeout=15)
            except requests.RequestException as exc:
                print(f"ERROR  {url}  ({exc})")
                continue
            if resp.status_code != 200:
                target = resp.headers.get("Location", "")
                print(f"{resp.status_code}    {url}  {target}")


if __name__ == "__main__":
    main(sys.argv[1], *sys.argv[2:3])

Adjust the column name to match your export. For each URL that returns 404 or 410, add a 301 redirect to the most relevant live page. For URLs that pass through multiple redirects, point them straight at the final destination. Also search for unlinked brand mentions, where a site names your company or product without linking, and politely ask for a link.

4. Strengthen Internal Linking

Internal links do not change Domain Authority, which is a domain-level measure of external links, but they do change how authority flows to your individual pages, and they affect Page Authority and real rankings. Link from your strongest pages (the ones with the most backlinks) to the pages you most want to rank, using descriptive anchor text.

5. Consolidate Duplicate and Split Properties

If your content is spread across several domains or subdomains, links are being split between them. Merging thin, overlapping sites into one, with proper 301 redirects, concentrates your link profile on a single domain. If you are planning this, follow a careful process like the one in how to move a website to a new domain without losing SEO.

6. Be Patient

DA updates when Moz recrawls the web and refreshes its index, and new links can take weeks to be discovered. Expect gradual movement over months, not days.

What Not to Do

The size of the market for "DA" is exactly why it is easy to game, and why gaming it is a waste of money:

• Do not buy links to raise DA. Google's spam policies explicitly list buying or selling links that pass ranking credit as link spam. Purchased links can raise third-party scores while doing nothing, or harm, in Google.
• Be skeptical of "high-DA" guest post marketplaces. Many of these sites have inflated metrics from link schemes and receive little real traffic. Check whether a site actually ranks and has an audience before seeking a link from it.
• Do not judge a domain purchase on DA alone. Expired domains are sometimes sold on their DA, but the links behind it may be spammy, irrelevant, or about to disappear. Review the backlinks and history yourself, using a process like the one in how to check a domain's history. Google also has a specific spam policy against expired domain abuse.
• Do not expect a disavow file to change DA. Third-party tools do not see your Google disavow file. Google itself says most sites do not need to disavow anything, because its systems already ignore most spammy links.

Domain Authority and Domain Age

People often assume older domains automatically have higher authority. In practice, older sites tend to have higher DA simply because they have had more time to accumulate links. Age itself is not the driver. We cover this in detail in how domain age affects SEO rankings.

Domain Authority FAQ

Conclusion

Domain Authority is a useful lens, not a goal. It is Moz's estimate of how competitive a domain is likely to be in search, built largely from link data, and it sits alongside similar third-party metrics like Ahrefs Domain Rating and Semrush Authority Score. None of them are Google ranking factors, and none of them should be compared across tools. Their real value is benchmarking your link profile against the specific competitors you face.

The ways to improve DA that are worth your time are the ones that would help you even if the metric did not exist: publishing resources that deserve to be cited, getting them in front of people who write about your field, reclaiming links lost to broken URLs, and consolidating split properties. Skip the shortcuts that only move a number, and both the score and your rankings will follow the work.

Here are some useful references for going deeper on domain authority and link signals:

1. Moz: What is Domain Authority? — Moz's own explanation of how the metric is calculated and how it should be used.
2. Semrush Knowledge Base: Authority Score — how Semrush combines link power, traffic, and spam factors.
3. Google Search Central: Spam policies for Google web search — defines link spam and expired domain abuse.
4. Google Search Central: How Search works — Google's overview of crawling, indexing, and ranking.
5. Google Search Central: Link best practices — how Google discovers and interprets links and anchor text.