These three suites overlap far more than their marketing suggests. All three do keyword research, backlink analysis, rank tracking and a site audit, and for the overwhelming majority of sites any of them would be a defensible choice. The interesting question is not which is best in general. It is which one to commit to, since the value of a suite comes mostly from the history it accumulates while you use it.
This is written from the angle I work at, which is technical SEO and indexing, so it weights the site audit and the crawl data heavily and the content marketing features lightly. If your job is mostly content planning, weight it differently and reach a different answer honestly.
The short answer
Ahrefs if the link graph is the thing you look at most, and if you would rather have a fast dataset than a guided workflow.
Semrush if you need breadth across SEO, paid search and competitor tracking in one place, and if more than one person who is not an SEO will use it.
Moz if the vocabulary and the learning curve matter more than the depth, or if your organisation already speaks in Domain Authority.
None of the three answers the question I get asked most, which is why a specific page is not indexed. No suite does. That comes from Search Console and from inspecting the URL, which is why the indexing guides on this site lean on those rather than on a crawler’s opinion.
Where they actually differ
The link index. This is the real dividing line. Each vendor runs its own crawler and its own retention rules, so the three indexes genuinely disagree about what links exist. Ahrefs built its reputation here and it remains the reason most people who pay for it do. The practical consequence is that cross-tool link counts are not comparable, and any argument that starts by comparing them is not an argument about your site.
Keyword data. All three model volume rather than measure it, because nobody outside Google measures it. The numbers will differ between tools for the same term and none of them is the truth. What matters is that you use one consistently, so that relative comparisons inside your own list mean something.
The site audit. Semrush’s is the broadest and the noisiest, in the sense that it flags a great deal and leaves you to triage. Ahrefs’ is tighter. Moz’s is the most readable and the least deep. For technical work, a crawl you trust matters more than the number of checks it claims, and all three will find the obvious things.
Everything else. Content tools, PPC data, local features, reporting. This is where the feature comparison tables get long and where the difference to your outcome is smallest.
What none of them can tell you
Worth being blunt, because it is the gap that costs people the most.
Why a page is not indexed. A suite can tell you a page exists and has no links. It cannot tell you what Google decided about it. That answer lives in the URL Inspection tool and in the Pages report, and the guide to reading it is crawled, currently not indexed.
Whether Google has your page at all right now. Index status in a third-party tool is inference. Checking it properly at scale is its own job, which is why the bulk URL inspection tool on this site exists and reads from the Search Console API rather than guessing.
Whether AI search engines mention you. None of the three reports this, because there is no report to consume. The measurement has to be built by hand, and the procedure is in how to track brand mentions in AI search.
How to actually choose
Three questions, in this order.
What do you open every week? Not what the tool can do, what you will use on a Tuesday. If that is backlinks, Ahrefs. If it is a mixed dashboard several people read, Semrush. If it is one report you want to understand without training, Moz.
Who else touches it? A suite used by one specialist should be chosen for depth. A suite that a client or a manager will open should be chosen for legibility, and that changes the answer.
How long will you keep it? The history is the asset. If you will switch in six months to save money, buy the cheapest thing that does the job, because you are not going to accumulate the value that makes the expensive one worth it. If you are committing for years, the ranking of the three on features today matters less than which interface you will not resent.
Then stop comparing. The most expensive mistake in this category is not choosing the wrong suite. It is spending a year rotating between trials and never building a year of data in any of them.
The comparisons on either side of this one
If you have narrowed it to two, the head-to-heads go deeper on the specific tension in each pair: Ahrefs vs Moz is the authority-metric argument, Ubersuggest vs Ahrefs is the budget question, and Ahrefs vs SpyFu vs Semrush is the one to read if competitor research is the actual job.
And if what you want from a suite is to find out why Google is ignoring your pages, that is not a tooling problem. It is indexing, and it starts with Search Console.
Quick answers
Can I just use the free tiers of all three?
You can, and for a single small site it is a reasonable position, but you will hit the same wall in each: the free tiers cap the row counts and hide the historical view, which are the two things that make a suite worth paying for. The more useful free stack is Search Console for your own site, which is complete and free, plus one paid suite for the competitive picture you cannot get anywhere else. Paying for three partial views of the same data is the worst of the options.
Do these tools show the same backlinks?
No, and the differences are large enough that comparing raw counts across tools is meaningless. Each runs its own crawler with its own discovery, refresh cadence and rules about what to keep, so a link present in one index can be absent from another for weeks or permanently. What this means practically is to pick one and track the trend inside it. A number that went up in your chosen tool is a signal. A number that is higher in one tool than another is not.
Which one is best for a beginner?
Semrush, on interface alone, because it walks you into a workflow rather than handing you a dataset. That is also its downside once you know what you are doing, since the guided path is slower than going straight to the report you want. Ahrefs assumes you already know what you are looking for. Moz sits between the two and is the gentlest on the vocabulary, which matters more than people admit when you are learning.
Do I need any of them if I have Search Console?
For your own site, Search Console is better than all three: it is the actual data rather than a model of it, it covers every query you appeared for, and it costs nothing. What it cannot show you is anyone else. Everything a suite adds is either competitive, which Search Console structurally cannot provide, or convenience over data you already have. Decide which of those you are buying before you compare tiers.
How often should I re-evaluate the choice?
Rarely, and that is the point of standardising. The switching cost is not the subscription, it is that your historical view resets and your team relearns an interface. Unless the tool you are on has stopped covering a job you do weekly, staying put is usually the higher-value decision. Re-evaluate when the work changes, not when a competitor ships a feature.