Domain Authority

What Is Domain Authority (DA)?

Domain Authority is Moz’s estimate of how well a domain will perform in organic search. It was introduced as a way to move beyond single-metric evaluations — like counting backlinks — and offer a composite score that reflects the overall strength of a website’s link profile.

The score runs from 1 to 100 and is logarithmic: moving from 10 to 20 is far easier than moving from 70 to 80. This design mirrors real-world ranking dynamics, where competing in highly competitive SERPs demands exponentially more authority.

DA is relative, not absolute. A score of 40 might be excellent for a local bakery but weak for a national insurance comparison site. The metric only becomes meaningful when compared against sites targeting the same keywords and audience.

How Domain Authority Differs from Page Authority

While Domain Authority measures the strength of an entire domain, Page Authority (PA) scores a single URL. Both are Moz metrics on a 1–100 logarithmic scale, and both rely heavily on backlink signals. A blog post that earns thousands of editorial links can have a PA far higher than the domain’s overall DA — and can rank well even on a lower-authority site.

Domain Authority vs. Domain Rating vs. Authority Score

Different SEO platforms use different names for conceptually similar metrics. Each is calculated differently, so scores do not translate one-to-one across tools.

Using two or more of these metrics together gives a fuller picture. If your DA is 45 but your DR is 30, investigate the discrepancy — it often points to differences in how the tools weigh link quality versus link volume.

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How Is Domain Authority Calculated?

Moz calculates DA using a machine-learning model trained on actual SERP results. The model compares the link profiles of thousands of domains against their observed ranking positions and identifies which factors best predict ranking performance.

While the full list of factors is proprietary, Moz has confirmed that the calculation weighs over 40 signals. The most influential include:

• Linking root domains: The number of unique websites linking to yours. This is the single strongest predictor. One link from 50 different domains is worth far more than 50 links from one domain.
• Total backlink count: The aggregate number of inbound links, moderated by quality.
• Link quality and relevance: Links from high-authority, topically relevant sites carry more weight than links from unrelated or low-quality domains.
• Spam score: Moz’s assessment of potentially manipulative links. A high spam score can suppress DA.
• Domain-level link equity: How link authority flows across the entire domain, not just individual pages.

Because DA is trained against real ranking data, Moz periodically updates the algorithm — most recently with DA 2.0. When the algorithm changes, your DA may shift even if your backlink profile hasn’t changed. This is normal and is covered in more detail below.

Why Did My Domain Authority Change?

A DA fluctuation does not always mean your site improved or declined. Common causes include:

• Algorithm updates from Moz: When Moz retrains its model, all scores are recalculated. Your DA may rise or fall relative to the broader web.
• Competitor movement: DA is relative. If competitors aggressively build quality links, your score can drop even if your own profile is stable.
• Link loss: High-quality backlinks that are removed or lost (e.g., a referring site shuts down) can reduce DA.
• Index growth: As Moz’s Link Explorer index expands, it discovers more links — which can surface previously unknown low-quality links pointing to your site.
• Spam score changes: If Moz reclassifies certain links as spammy, your score may adjust.

The best response to a DA drop is to check whether your organic traffic and rankings have actually changed. If they haven’t, the DA movement is likely a measurement artifact, not a real problem.

Is Domain Authority a Google Ranking Factor?

No. Google does not use Domain Authority — or any third-party authority metric — in its ranking algorithms. Google’s John Mueller has stated this repeatedly, and Google’s own documentation confirms that the search engine evaluates pages on hundreds of granular signals, not a single composite score.

However, DA correlates with ranking performance because it measures many of the same underlying signals Google uses: the quality and quantity of inbound links, domain-level trust indicators, and content strength. A site with a DA of 80 tends to rank better than a site with a DA of 20 — not because Google reads the DA number, but because the high-DA site almost certainly has a stronger backlink profile, more referring domains, and better overall SEO health.

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What Is a Good Domain Authority Score?

There is no universal “good” DA. What counts as strong depends entirely on your competitive landscape.

If your DA is 35 and competitors average 50, the gap signals a need to invest in link building and content quality. If your DA is 35 and competitors average 30, your link profile is already competitive — focus on content depth and on-page optimization instead.

Is 20 a Good Domain Authority Score?

A DA of 20 is typical for a new or small website with a modest backlink profile. For a local business or a niche blog, 20 can be perfectly adequate to rank for low-competition keywords. For a national brand, 20 is below competitive range. The score itself is neutral — its adequacy depends on who you’re competing against.

Why Is Domain Authority Important for SEO?

DA is important not because it directly affects rankings, but because it serves as a leading indicator of your site’s competitive position. It helps you:

• Prioritize link-building targets: Sites with higher DA than yours — but not astronomically higher — are realistic targets for guest posts, partnerships, and outreach.
• Evaluate potential domains for acquisition or partnership: Before buying a domain or entering a content partnership, checking its DA helps you estimate the SEO value it brings.
• Track long-term SEO progress: DA trends over 6–12 months reflect whether your off-page SEO strategy is working, even as rankings fluctuate week to week.

How to Check and Track Domain Authority

Several free and paid tools provide authority metrics. The right choice depends on how many domains you need to check and how deeply you need to analyze the data.

• Moz Link Explorer: The native home of DA. Free tier allows limited lookups; Moz Pro unlocks bulk checking and historical tracking.
• MozBar: A free browser extension that displays DA, PA, backlink counts, and linking root domains for any page you visit — useful for quick competitive checks while browsing SERPs.
• Ahrefs Site Explorer: Shows Domain Rating (DR) alongside backlink growth charts, referring domain trends, and organic keyword data.
• Semrush Domain Overview: Displays Authority Score plus traffic estimates, keyword rankings, and backlink profile summaries.
• Majestic: Provides Trust Flow and Citation Flow, which together distinguish link quality from link volume.

For regular monitoring, pick one primary tool and check monthly. Authority metrics move slowly; weekly checks add noise without insight.

How to Increase Your Domain Authority

Improving DA is a byproduct of improving your site’s overall SEO health — particularly its backlink profile. There is no shortcut. Tactics that promise quick DA gains (link farms, paid link schemes, mass directory submissions) are likely to backfire by inflating your spam score.

1. Earn High-Quality Backlinks from Authority Sites

The single most effective way to raise DA is to earn links from domains that themselves have high authority.

Other sites link to data they can cite.

• Guest posting on reputable sites: Write for established publications in your niche. One link from a domain with DA 70+ is worth more than dozens of links from DA 10 blogs.
• Creating linkable assets: Tools, templates, calculators, and definitive guides attract editorial links naturally.
• Digital PR: Earn mentions in news outlets and trade publications by offering expert commentary or newsworthy data.

2. Develop a Strong Internal Linking Strategy

Internal links distribute page-level authority across your domain. A well-structured internal linking architecture helps search engines understand which pages are most important and ensures link equity flows to key pages. Use descriptive anchor text, link deep (not just to your homepage), and audit for orphan pages that receive no internal links.

3. Audit and Remove Toxic Backlinks

Not all links help. Links from spammy, irrelevant, or penalized sites can raise your spam score and suppress DA. Use Moz’s Spam Score tool, Ahrefs, or Semrush to identify toxic links. For links you cannot get removed manually, use Google’s Disavow Tool — but only as a last resort and only for clearly harmful links. Over-disavowing can hurt more than it helps.

4. Optimize Your Website Structure and User Experience

While DA is primarily a link-based metric, the underlying signals it models correlate with user experience. A fast, mobile-friendly, well-structured site earns more links, retains visitors longer, and sends positive engagement signals. Ensure your site loads quickly, has clear navigation, uses HTTPS, and avoids intrusive interstitials.

5. Create Content That Earns Links Consistently

One viral post isn’t enough. Sustainable DA growth comes from consistently publishing content that solves real problems for your audience. When every piece of content is worth referencing, backlinks accumulate naturally over time — and DA follows.

How to Use Domain Authority in Your SEO Strategy

DA works best as a directional compass, not a daily dashboard metric. Here is a practical workflow for affiliate program managers, advertisers, and publishers:

1. Quarterly competitive audit: Check your DA and the DA of your top five SERP competitors. Note the gap and whether it’s widening or narrowing.
2. Link prospect qualification: When evaluating sites for guest posting or partnership, filter by DA range. Target sites 10–20 points above your own — they’re authoritative enough to move the needle but realistic to secure links from.
3. Content investment decisions: If a competitor with a lower DA outranks you for a high-value keyword, the opportunity is on-page: their content is likely better matched to search intent. If a competitor with a much higher DA outranks you, the gap is likely authority-driven — invest in link building for that page.
4. Domain acquisition due diligence: Before buying an expired domain or partnering with a content site, check its DA alongside its traffic trend. A high DA with declining organic traffic may indicate a penalty or outdated content.

Limitations of Domain Authority

DA has meaningful blind spots that every practitioner should understand:

• Not a Google signal: DA does not influence your rankings. A DA increase without corresponding improvements in real ranking factors (links, content, technical SEO) will not change your SERP position.
• Logarithmic scale masks progress: Moving from 20 to 30 is a significant improvement. Moving from 70 to 75 may represent an even larger absolute gain in link equity, but it looks smaller on the 1–100 scale.
• Tool-dependent scores: Your DA from Moz, DR from Ahrefs, and AS from Semrush will differ. None is “correct” — each uses a different methodology. Cross-reference rather than fixating on one number.
• Ignores on-page and technical factors: A site with DA 60 but thin content, poor Core Web Vitals, and no structured data will still underperform a DA 30 site with excellent content and technical execution for specific queries.
• Link index coverage varies: Each tool crawls a different portion of the web. A backlink visible in Ahrefs may not appear in Moz’s index, and vice versa. This affects scores.

Obsolete Practices to Avoid

Several once-common DA tactics are now counterproductive:

• Link exchanges and reciprocal linking schemes: Google’s SpamBrain and Moz’s spam detection both penalize unnatural link patterns.
• Mass directory submissions: Low-quality directories are ignored at best and toxic at worst.
• Comment spam with keyword-rich anchors: These links are nearly always nofollowed and can trigger spam flags.
• Buying links from PBNs (private blog networks): High risk of manual action from Google and inflated spam scores in Moz.
• Chasing DA for its own sake: Building links solely to raise a third-party metric, without regard for relevance or traffic, wastes resources.