Backlink Checker Guide: Free Tools, Ahrefs and Authority Scores

A backlink checker shows which websites link to a page or domain, how many unique sites those links come from, and how strong those sites appear to be. It is the starting point for understanding your authority in search, spotting risky links and finding link opportunities your competitors already have.

Every checker is built on its own crawl of the web, so no two tools report exactly the same numbers. Knowing what the data means, and what it does not, matters more than which tool you pick.

What a backlink checker tells you

Most tools report the same core metrics, even if they name them differently:

• Total backlinks: every individual link found pointing to the target.
• Referring domains: the number of unique websites linking. This is usually more meaningful than total links, since one site can link hundreds of times from a sidebar.
• Anchor text: the clickable words used in links. A natural profile is dominated by brand names and URLs, with a mix of descriptive phrases.
• Follow vs nofollow: whether links carry attributes such as nofollow, sponsored or ugc.
• New and lost links: changes over time, useful for spotting campaigns or problems.
• Authority metric: a vendor score estimating the strength of the linking site or the target.

The best backlink checker options compared

Tool	Free access	Authority metric	Best for
Google Search Console	Free for verified sites	None	Seeing links Google has found to your own site
Ahrefs	Free backlink checker with limited results; Ahrefs Webmaster Tools for your own sites	Domain Rating (DR)	Deep link analysis and competitor research
Semrush	Limited free queries with an account	Authority Score	Combining link data with wider marketing research
Moz Link Explorer	Limited free queries with an account	Domain Authority (DA)	Quick authority comparisons
Majestic	Primarily paid; check current options	Trust Flow and Citation Flow	Link-focused research

Free tiers and limits change over time, so check each vendor's current terms.

Using the Ahrefs backlink checker

The free Ahrefs backlink checker gives you a snapshot of any domain or URL: its Domain Rating, counts of backlinks and referring domains, and a sample of top links. It is a preview of the paid Site Explorer tool, which shows the full link list, history, anchors and filters.

To get the most from it:

1. Check your own domain first to set a baseline.
2. Run your top three competitors and note which sites link to them but not to you.
3. Look at the linking pages, not just the domains. Is the link inside useful content, or buried in a footer?
4. For your own site, verify ownership in Ahrefs Webmaster Tools to see far more of your link data at no cost.

If you are weighing up Ahrefs against other suites, our Serpstat vs Ahrefs comparison breaks down the differences.

Domain authority checker scores: what they really mean

A domain authority checker returns a single number, usually on a 0 to 100 or 1 to 100 scale, that predicts how strong a site's link profile is relative to others in that vendor's index. Moz's Domain Authority is the best known, alongside Ahrefs' Domain Rating and Semrush's Authority Score.

Keep three things in mind:

• They are not Google metrics. Google does not use DA, DR or Authority Score in its rankings. They are third-party estimates.
• They are relative and often logarithmic. Moving from 20 to 30 is much easier than moving from 70 to 80.
• Scores from different tools are not comparable. A DA of 40 and a DR of 40 measure different things on different data.

Use these scores to compare sites within the same tool and to prioritize outreach, not as goals in their own right.

How to judge backlink quality beyond the numbers

A strong link usually ticks most of these boxes:

• Relevance. The linking site covers topics related to yours, or serves the same audience.
• Real audience. The site gets genuine organic traffic and engagement.
• Editorial placement. The link sits in the main content and was given because it helps readers.
• Natural anchor text. Brand or descriptive anchors, not repeated exact-match keywords.
• Trustworthy neighborhood. The site does not link out to spam, gambling networks or unrelated paid placements.

Warning signs include sudden spikes of links from unrelated foreign-language sites, sitewide footer links, link farms and pages that exist only to sell links. Automated link schemes are one of the fastest ways to end up with a problem profile, as we explain in our article on backlink generators and automated link building.

Turning backlink data into action

A checker is only useful if it changes what you do next:

1. Find link gaps. List sites linking to two or more competitors but not to you. These are your warmest prospects.
2. Reclaim lost links. If a valuable link disappeared because a page moved, ask for an update or restore the URL with a redirect.
3. Fix broken pages with links. Pages returning 404 errors waste the links pointing at them; redirect them to the closest relevant page.
4. Create linkable assets. Original data, tools, guides and visuals earn links far more readily than sales pages.
5. Monitor monthly. Track new and lost referring domains to catch both wins and spam attacks.

For budget-conscious campaigns, our guide to affordable link building services explains what to look for in a provider. If you want the analysis and outreach handled for you, Pro Pixel's SEO services include link audits and white-hat link building.

Frequently asked questions