What Is Domain Authority? The Honest Guide

By Mubashir Safeer✓Updated 12 Oct 20269 min read

Domain Authority is the most quoted — and most misunderstood — number in SEO. It’s a 1–100 score that predicts how well a site might rank, but it’s not from Google, and Google doesn’t use it.

This guide explains what DA actually is, how Moz calculates it, what the score means for your site, and how to use it without getting fooled.

What Is Domain Authority?

Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how likely a website is to rank in search engine result pages (SERPs). Scores range from 1 to 100, with higher scores indicating a greater likelihood of ranking.

Moz created DA as a comparative metric. As Moz’s former principal search scientist Russ Jones put it, DA is most powerful when comparing sites against each other — not when viewed in isolation. A DA of 40 means nothing by itself; it means a lot when your three competitors are at DA 35, 42, and 55.

You can check any site’s Domain Authority for free with our website authority checker.

The score comes from a machine learning model (since the DA 2.0 update in 2019) trained against real Google search results. Moz feeds the model signals from its own web index — primarily link-related data — and the model learns which patterns correlate with high rankings.

How Moz Calculates Domain Authority

Moz doesn’t publish the exact formula (it’s proprietary), but they’ve confirmed the key inputs:

• Linking root domains: The number of unique websites linking to you. This is the strongest signal — 100 links from 100 domains beats 1,000 links from 10 domains.
• Total number of links: The raw count of inbound links, though this matters less than domain diversity.
• MozRank: Moz’s measure of link popularity — how many links point to you, weighted by the authority of those linking pages.
• MozTrust: How closely your site is connected to trusted seed sites (universities, government pages, major news outlets). Links from trusted neighborhoods boost this.
• Spam patterns: The model penalizes manipulative link profiles — unnatural anchor text distributions, links from known spam networks, and sudden spikes from low-quality domains.

All of these feed into a single score on a logarithmic scale from 1 to 100. Logarithmic means each step up requires exponentially more authority. Going from DA 20 to DA 30 might take 50 new referring domains; going from DA 70 to DA 80 might take 5,000.

This is why new sites see fast DA movement (jumping from 1 to 15 feels easy) while established sites barely budge. It’s also why comparing a DA 25 site to a DA 50 site isn’t a 2x difference — it’s closer to a 10x difference in actual link authority.

Why DA Is Logarithmic (and What That Means for You)

DA runs on a logarithmic scale, not a linear one. Moving from DA 20 to DA 30 takes real but achievable effort — a few dozen quality links. Moving from DA 70 to DA 80 takes exponentially more, because you’re competing against sites with enormous link profiles.

Think of it this way: the gap between DA 25 and DA 50 isn’t a 2x difference in authority. It’s closer to a 10x difference in actual link power. Every point gets harder to earn as the score climbs, which is why new sites gain DA quickly at first and then plateau.

The practical takeaway: don’t chase a specific number. Chase the gap between you and the sites actually ranking for your keywords. If page one is full of DA 30 sites, reaching DA 35 wins — you don’t need DA 60.

Domain Authority vs. Other Metrics

DA isn’t the only authority score. Here’s how it compares:

These scores routinely disagree about the same website. A site might be DA 38, DR 52, and AS 44 simultaneously. None is “wrong” — they use different data, different formulas, and different update schedules.

For a detailed comparison, see our guide on DA vs DR: which metric matters more. The short version: pick one metric and stick with it for tracking. Switching between them creates confusion, not clarity. Curious where a site stands? Run it through our DR checker.

DA vs PA: Side-by-Side

A page can have high PA on a low-DA site (a viral post on a new blog) or low PA on a high-DA site (a buried page on Wikipedia). When prospecting links, check both: DA tells you the neighborhood, PA tells you the house.

What Is a Good Domain Authority Score?

There’s no universal “good” DA. It depends entirely on your competitive landscape:

DA 1–20: New or very small sites. Normal for blogs under a year old, local businesses just starting SEO, or niche sites with minimal link building. If your competitors are also in this range, you’re competitive.

DA 20–40: Established small-to-medium sites. You’ve earned real links and have a functioning content strategy. In many local and niche markets, DA 30+ is enough to dominate page one.

DA 40–60: Strong authority sites. National brands, popular blogs, well-established e-commerce stores. You’re competitive in moderately difficult keywords.

DA 60–80: Major players. Large media sites, top e-commerce brands, industry leaders. Very difficult to compete against without significant resources.

DA 80–100: The internet’s giants — Wikipedia, Amazon, YouTube, major news outlets. Unreachable for most sites, and that’s fine. You don’t need DA 90 to rank for your keywords.

The question that actually matters: what DA do the sites on page one for your target keywords have? If they’re all DA 25–35 and you’re at DA 28, you’re in the game. If they’re all DA 60+ and you’re at DA 15, you need a different keyword strategy (target longer-tail terms) while building authority over time.

What Domain Authority Doesn’t Tell You

DA is useful, but it has blind spots that trip up even experienced SEOs:

It’s not a Google ranking factor

Google does not use Domain Authority. Google’s John Mueller has confirmed this multiple times. DA is Moz’s prediction of ranking ability, not a signal Google reads. A high DA correlates with good rankings because strong link profiles cause both — but the score itself influences nothing.

It ignores relevance

A DA 65 cooking blog linking to your cybersecurity startup passes less value than a DA 35 cybersecurity blog would. DA measures raw link strength, not topical relevance. Two sites with identical DA can have wildly different ranking power for your specific keywords. See our DA vs rankings study of 70 real results for the data.

It can be manipulated

Spammers inflate DA by building thousands of low-quality links to throwaway domains, then sell “high DA guest posts.” A DA 45 site with gibberish content and zero traffic is worthless despite the number. Always check the site itself — real content, real audience, real relevance — before trusting the score.

It says nothing about traffic

A site can have DA 55 and get 500 visitors a month (strong links, poor content strategy) or DA 25 and get 50,000 visitors (great content, few links). DA measures link authority, not audience size. For partnership decisions, check traffic too.

The score fluctuates

DA updates when Moz refreshes its index (roughly monthly). Your score can drop 2–3 points with no changes on your end — the index shifted, competitors gained links, or Moz adjusted its model. Small fluctuations are noise. Only sustained trends over 3+ months signal real change.

How to Use Domain Authority Correctly

DA is a tool, not a goal. Here’s how to get value from it without obsessing:

Compare, don’t worship. Use DA to evaluate link opportunities (“Site A at DA 42 vs. Site B at DA 18”) and to benchmark against competitors. Don’t set “reach DA 50” as a business goal — it’s a vanity metric disconnected from revenue.

Track monthly, not daily. Check DA once a month alongside referring domain count and organic traffic. The three numbers together tell a story that DA alone can’t: are you earning links, is authority growing, and is it translating to visitors?

Pair it with human judgment. Before pursuing a link from a “high DA” site, open the site. Does it look real? Does it have an audience? Is it relevant to your niche? Ten seconds of human evaluation catches what no metric can.

Use it for prospecting, not for validation. DA helps you find link opportunities efficiently. It doesn’t tell you whether your SEO strategy is working — traffic and rankings do that. If DA is rising but traffic is flat, your links lack relevance.

For a practical plan to actually grow your score, read our guide on increasing your domain authority with realistic timelines and prioritized tactics.

Common Domain Authority Myths

DA attracts more misinformation than almost any SEO metric. Let’s clear up the worst myths:

Myth: “I need DA 50+ to rank.” You need to beat the specific sites ranking for your keywords. If page one is full of DA 20–30 sites, DA 35 wins. Targeting keywords where you can compete matters more than chasing an arbitrary number.

Myth: “DA updates in real time.” Moz refreshes its index roughly monthly. New links take weeks to appear in your score. Checking DA daily is pointless — the data behind it moves too slowly.

Myth: “A DA drop means Google penalized me.” DA and Google penalties are unrelated. DA drops usually mean index updates or relative shifts. A Google penalty shows up as traffic loss, not DA changes. Check Google Search Console for manual actions if you’re worried about penalties.

Myth: “All links count equally toward DA.” A link from a DA 80 site moves your score far more than 50 links from DA 10 sites. Moz’s model weighs link quality heavily. This is why buying bulk cheap links barely moves DA — the model discounts them.

Myth: “I should disavow all low-DA links.” Low DA doesn’t mean toxic. A DA 12 blog with real content in your niche is a legitimate link. Only disavow links that are clearly manipulative (link farms, hacked sites, paid schemes). Disavowing legitimate links hurts you.

How to Check Domain Authority for Free

Several tools show DA without payment:

• Moz Link Explorer (free tier): 10 queries/month with a free Moz account. Shows DA, linking domains, and spam score.
• MozBar (Chrome extension): Shows DA for any page you visit. Useful for quick checks while browsing link prospects.
• Our free checker: We run a free DA checker tool on this site — no signup, instant results with supporting metrics.

Don’t pay for a tool just to see a DA number. Every paid platform’s headline metric is still an estimate. Pay for the database behind it (historical data, larger index, API access) — not for the number itself.

Frequently Asked Questions

What does Domain Authority mean?

Domain Authority is Moz’s 1–100 score predicting how likely a website is to rank in search results compared to competitors. It’s calculated by a machine learning model using link data from Moz’s web index. Higher scores indicate stronger link profiles, but DA is not used by Google and should be treated as a comparative estimate, not an absolute measure of quality.

Is Domain Authority important for SEO?

Indirectly. DA itself doesn’t affect rankings (Google doesn’t use it), but the things that raise DA — earning quality backlinks from relevant sites — do improve rankings. Think of DA as a thermometer: it measures the temperature but doesn’t cause it. Focus on the underlying link building, and DA follows.

What is considered a good DA score?

It depends on your competition. For most small businesses and niche sites, DA 30–40 is competitive. The real benchmark is the DA of sites ranking on page one for your target keywords. If you match or exceed their link profiles, you can compete regardless of the absolute number.

How is Domain Authority different from Page Authority?

Domain Authority measures the ranking strength of an entire domain; Page Authority (PA) measures a single page. A site can have DA 50 while individual pages range from PA 15 to PA 65. For link building, DA helps evaluate sites; PA helps evaluate specific pages you’re trying to outrank.

Can Domain Authority go down?

Yes. Common causes: losing significant backlinks, Moz updating its index (your links didn’t change but the model did), competitors gaining links faster than you (DA is relative), or Google discounting spammy links in your profile. Small drops (1–3 points) are usually index noise. Large drops warrant a backlink audit.

Does Google use Moz Domain Authority?

No. Google has explicitly stated it doesn’t use DA or any third-party authority metric in its ranking algorithm. Google has its own internal signals for evaluating site authority. DA is useful for SEOs as a comparative tool, but it has zero direct impact on Google rankings.