MOZ, SEMrush or Ahrefs: Who's Telling the Truth About Your Domain Authority?

Your team walks into the meeting with the metrics ready. Ahrefs shows a Domain Rating of 45. Everyone smiles. In Moz, the DA reads 32. They glance at each other. SEMrush is opened… and its Authority Score is 21. Someone nervously asks, “So, which one is the real one?” That’s where the confusion begins.

It’s not that one tool is wrong. The truth is, none of them are measuring the exact same thing—or in the same way.

Domain authority isn’t a sacred, official, or absolute number. It’s an estimated metric that tries to predict how visible and trustworthy your website is to search engines. And while every tool presents it as a score from 0 to 100, each one uses its own formula, database, and interpretation of what that number means.

If you don’t understand what you’re looking at, you’re making important decisions with incomplete or misread data. And in SEO, that can cost you—big time.

In this blog, we break it down with zero fluff: how it’s calculated, what each tool really measures, and most importantly, how to use that information to grow. Yes, there’s a difference between DR, DA, and Authority Score. And yes, you’re about to understand exactly why.

Domain Authority Isn’t Dogma—It’s Interpretation

Domain authority is a technical construct—a way to estimate how much search engines trust your site. But like any estimate, it has nuance, limitations, and a margin of error. It’s not a direct signal from Google’s algorithm, but it is a useful proxy for how that algorithm might treat your site compared to others.

Think of it this way: if SEO were a card game, domain authority would be the level of your deck. It doesn’t guarantee you’ll win every hand, but it does influence how strong your play can be in the long run. It’s a way to assess how ready you are to compete for high-value keywords, especially against websites with more—or less—digital clout than yours.

And no, it’s not an absolute metric. It evolves over time, with each data update, every new link gained or lost, every technical error left unresolved, every piece of content created—or abandoned. It’s a living, dynamic metric that demands ongoing attention.

The tricky part? No tool has access to Google’s actual algorithm. They’re all making educated guesses based on public signals: links, mentions, site structure, estimated traffic. That’s why their numbers differ. Because even if they look similar, what they measure—and how they calculate it—isn’t the same.

The real value in understanding this? You stop obsessing over why the number won’t go up—and start using it as a real analysis tool. When you realize that domain authority isn’t a goal, but a byproduct of doing SEO right, your mindset shifts: from chasing numbers to building assets.

Related content: SEO: Increase your website’s visibility in search engines

Who’s Measuring—and How?

When we talk about domain authority, the same names always come up: Moz, Ahrefs, and SEMrush. But few people stop to understand why these three tools dominate the conversation—and more importantly, what role each one plays in a real SEO strategy.

These platforms aren’t oracles—they’re instruments. Think of them like a map, a compass, and an altimeter: none tells you everything, but together, they help guide your path.

The key differences lie in the data sources they use, the size of their indexes, how fast they crawl the web, and the ranking factors their algorithms prioritize. And that’s where the true value of each tool comes into play.

Moz – Domain Authority (DA)

Moz was the pioneer. It introduced the concept of “Domain Authority” when SEO was still in its infancy. Its approach focuses on the quality and quantity of links pointing to your site, using a scoring system that combines dozens of signals.

Its index is not the largest nor the most up-to-date, but its DA remains a useful reference if used comparatively within the same platform.

What’s interesting about Moz is that it offers clarity: you know what it measures, how it measures it, and you can use its free toolbar for quick analysis. But if you work in very specific markets or with new sites, it may not register relevant links because its crawler doesn’t go as deep as others.

Ahrefs – Domain Rating (DR)

Ahrefs became the favorite tool among link building experts for a reason: its crawler is second only to Google’s. That means it detects new links faster, has a broader database, and offers an almost real-time view of your backlink profile.

DR (Domain Rating) measures the strength of your external link profile, but it doesn’t take into account traffic, user experience, or content signals. Is that a limitation? It depends on what you’re analyzing. If you want to know how strong your link network is, DR is the key metric. But if you want to evaluate your domain’s overall performance, you’ll need to complement it with other tools.

Additionally, Ahrefs lets you identify which referring domains are most worthwhile, how authority is distributed among your internal pages, and what link opportunities you’re missing out on.

SEMrush – Authority Score

The most demanding of the group. And rightly so. SEMrush doesn’t just count links—it also evaluates the context and overall health of the site. Its Authority Score takes into account estimated organic traffic, user behavior, link profile toxicity, and even the domain’s trust level.

This makes it a metric closer to a “global grade” for the site. The result: its scores are usually lower, even for sites with good technical SEO and good content. But they are also more useful if you’re looking for a comprehensive view.

Where SEMrush shines is in full diagnostics: Do your links really help? Does your site attract quality organic traffic? Are there signs that Google might distrust your domain? All of that is reflected in the score.

Which is better for measuring domain authority?

That is not the question. The right question is: Which one helps me the most for what I need today? Because choosing the wrong tool doesn’t just confuse you—it can also make you lose time, budget, and credibility in your own strategy.

• Are you starting to build links and need to know if they’re working? Ahrefs gives you a quick and detailed read of your backlink network.
• Do you want to compare your domain with other players in your sector or evaluate basic changes over time? Moz is enough to have a reference point.
• Are you looking for a global view of your site, including links, traffic, toxicity, and reputation signals? SEMrush gives you that full diagnosis.

But beyond which one you choose, there’s something fundamental: don’t mix tools month to month as if they were the same.

If this month you track with Moz, the next with SEMrush, and then with Ahrefs, you’re not measuring evolution. You’re comparing apples to oranges, on different trays, with different rules.

Tuatara – SEO Agency in Colombia

If you’re looking at these metrics without knowing what decisions to make, it’s worth having someone with experience help you read between the lines. At Tuatara, we’ve spent years analyzing the evolution of domain authority across different industries, working with brands starting from scratch and others looking to scale smartly. We understand how each tool behaves, what types of links truly add value, and which tactics do more harm than good.

A healthy domain authority is not built by publishing more, inflating reports, or copying what the competition does without understanding the context. It’s built through coherent decisions: useful content, a solid structure, strategic digital relationships, and sustained focus over time. Every action adds or subtracts. And that holistic vision is what we apply to every project.

We help you make that number represent reputation, visibility, and trust. Because when your domain has real authority, every piece of content performs better, every link carries more weight, and every visit is closer to becoming a sale. That’s the difference between doing SEO and having a digital strategy designed for growth.