Backlinks are links from other websites that point to a domain. When site A links to site B, that's a backlink for site B. They're the foundation of how search engines measure authority. More high-quality backlinks generally means better rankings.
How backlinks work as a ranking signal
Google's original PageRank algorithm was built entirely on backlinks. The idea was straightforward: if other sites link to you, your content must be worth something. The more authoritative the linking site, the more value that link passes.
Not all backlinks are equal. A link from the New York Times carries far more weight than one from a random blog with no traffic. And a dofollow link passes authority while a nofollow link doesn't. Quality beats quantity every time.
Context matters too. A backlink from a health website to a health domain is more relevant than the same link to a tech site. This is where Topical Trust Flow comes in: it tells you whether a domain's backlinks come from relevant sources.
Backlinks and expired domains
The main reason people buy expired domains is their backlink profile. A domain that operated as a real business for 10 years likely earned editorial backlinks from real websites. Those links still exist even after the domain expires. When you acquire that domain and put content on it (or redirect it), you inherit that link equity.
But there's a catch. Some expired domains have toxic backlinks from spam campaigns, link farms, or PBN networks. These can actually hurt your SEO. Always examine the link sources, not just the count. A domain with 200 clean backlinks from 150 referring domains is far more valuable than one with 10,000 backlinks from 50 spammy sites.
Backlinks on CatchDoms
CatchDoms displays the total backlink count for each domain alongside the dofollow percentage. This data comes from DataForSEO and SEObserver. You can filter for domains that have backlinks. And the platform's scoring algorithm factors backlink count into the overall quality rating.