The best backlink analysis tool: what each one indexes, and how to pick by the job

The best backlink analysis tool is the one whose link index covers the sites you care about and whose report answers the single question you opened it for. Four questions cover almost all backlink work: what does my own profile look like, is this site worth a link from, where are my competitors getting links I am not, and what have I gained or lost this month. Google Search Console answers the first for free and only for your own site. Ahrefs, Semrush, Moz Link Explorer and Majestic each run their own web crawl and answer all four, with different indexes and different scoring. This page sets out what each one is strongest at and gives a repeatable way to run the analysis.

This page covers choosing and using a link analysis tool. For what makes a link valuable in the first place, see what a backlink is.

The one thing that separates these tools

Every link tool reports from its own crawl of the web. None of them sees Google's index. So two tools will give you two different link counts for the same domain, and neither is wrong: they found different things. What follows from that is simple and useful:

• Index size and refresh rate matter more than the interface. A link discovered three weeks late is a link you acted on three weeks late.
• Authority scores are vendor metrics. Domain Rating, Authority Score, Domain Authority and Trust Flow are each one company's model on one company's index. They are useful for sorting a list, and they are not numbers Google holds.
• Pick one tool as your system of record. Comparing this month in one tool to last month in another produces movement that is really just a different crawl.
• Keep Search Console in the mix. It reports links Google itself has seen to your site, which is the one view no third party can reproduce.

The tools, by the job they suit

Tool	Known for	Best job for it	Free view
Ahrefs	Large and frequently refreshed link index, Domain Rating, link intersect	Competitor link gap work and prospect vetting	Limited free backlink checker and free Webmaster Tools for a verified site
Semrush	Backlink audit with a toxicity view, and link data alongside keyword and traffic data in one account	Cleaning up an inherited profile, and reporting next to rankings	Capped free queries per day
Moz Link Explorer	Domain Authority and Page Authority, spam score, link building prospect lists	Teams whose reporting already uses Domain Authority	Free queries with an account
Majestic	Trust Flow and Citation Flow, topical trust categories, historic index	Judging the topical relevance of a link profile	Limited free summary data
Google Search Console	Links Google has seen to your verified site	Your own profile, and confirming a link has been found	Free, your own site only

If you are already paying for one suite, the practical answer is usually to use that one properly before buying a second. Semrush users can start with the Semrush backlink audit, and Ahrefs users with what the free Ahrefs checker shows.

The metrics, translated

• Referring domains is the number that matters most. One hundred links from one site is one relationship. One hundred links from one hundred sites is one hundred.
• Dofollow and nofollow describes the link attribute. Nofollow, sponsored and ugc links still bring people and still signal that you exist.
• Anchor text distribution should look like the way people actually write. A profile where the same commercial phrase appears in most anchors looks built rather than earned.
• New and lost links is the report to put on a monthly schedule, because a lost link from an important page is worth an email.
• Toxicity and spam scores are heuristics for triage. Use them to shortlist what to look at by hand, not to decide anything on their own.
• Authority scores rank candidates against each other. Do not read a two point difference as meaningful.

How to run a backlink analysis in eight steps

1. Verify your site in Search Console and export the links report. This is your baseline.
2. Run your domain in your chosen tool and record referring domains, total links, and the authority score. Save the date.
3. Sort referring domains by authority and read the top fifty by hand. You are looking for which pages link to you and why.
4. Check the anchor text distribution for anything repetitive or commercial enough to look deliberate.
5. Run three competitors and use the link intersect or link gap report to list domains linking to two of them and not to you. That list is your outreach shortlist.
6. Vet each prospect before you approach it: real traffic, real editorial pages, a topic near yours, and outbound links that look chosen rather than sold.
7. Flag anything you would be uncomfortable explaining, and decide between leaving it, asking for removal, or disavowing. Disavow is a last step, not a reflex.
8. Set the new and lost links report to a monthly cadence so you are always working from current data.

Step five is where the value is. Everything upstream of it is inventory. For what to do with the shortlist, see what earns links now and which link tactics hold up.

Checking a single prospect quickly

You do not need a full audit to decide on one site. Five checks take about four minutes:

• Does it get search traffic of its own, on topics near yours?
• Does it publish editorial pages with named authors, or only guest posts?
• Are its outbound links relevant, or is every third paragraph a different industry?
• Is there a paid placement page hidden in the footer?
• Would you be happy for a customer to arrive from that page?

Operators and site queries still find a lot of this in Google itself, covered in how to find backlinks in Google.

Which backlink tool has the biggest index?

Ahrefs, Semrush and Majestic all publish index statistics and all three are very large. Rather than taking a published figure, run two or three of your own competitor domains through the free views and see which tool finds the links you already know exist.

Is a free backlink checker enough?

For spot checks and prospect vetting, yes. Free views cap the number of rows you can export, so once you are working a competitor gap list of hundreds of domains a paid seat saves more time than it costs.

Does Domain Authority affect Google rankings?

Domain Authority is Moz's own prediction, and Google does not use it. It is a sorting aid for your prospect list. Relevance of the linking page and whether a real audience reads it are the things to judge on.

How often should I audit my backlinks?

A full audit once or twice a year, and the new and lost links report monthly. Also run one after a migration, because redirect mistakes are where link value quietly disappears.

Do I need to disavow bad links?

Most sites never need to. Google ignores the great majority of low quality links on its own. Reach for the disavow file when you have a manual action in Search Console or a profile you know was built by paid placement.

Which tool shows what the assistants cite

Each tool here indexes the web in its own way and attaches its own score. None of them indexes the answer itself. If your question is who gets named when a buyer asks an assistant about your market, an index of links gives you a clue only. The direct route is to ask the question and open the sources. AI Knows Us records those sources next to the names, so you can compare the link picture with the citation picture for the same domain.