Definition
A backlink is a hyperlink on another website that points to a page on yours. Search engines read backlinks as evidence about a page: what it is about, from the link text and surrounding words, and how much other sites trust it, from who links to it.
Links have been part of Google's ranking since its PageRank algorithm in 1998, and they still are. Google's guide to its ranking systems says it has 'various systems that understand how pages link to each other' and that PageRank, although it 'has evolved a lot', remains part of its core ranking systems. Google also fights manipulation: buying links or joining link schemes violates its spam policies and can lead to a manual action, and its systems typically ignore links from known spam sites.
Not every link counts the same. A link carries more weight when it comes from a site with its own strong link profile, sits inside editorial text rather than a footer or comment, is topically related to the page it points to, and uses descriptive anchor text. Links marked rel='nofollow', rel='sponsored' or rel='ugc' tell search engines not to treat the link as an endorsement. Third-party metrics such as domain authority or domain rating try to summarize a site's link profile in one number; they are useful for comparison but are not Google scores.
In AI search, backlinks work indirectly. ChatGPT, Perplexity, Copilot and Google's AI Overviews retrieve pages through search indexes before they cite them, so pages that rank well in Google or Bing, partly thanks to links, are more likely to enter the candidate set. Links also help crawlers discover new pages. But AI systems then choose passages, not domains, and they reward a direct answer to the sub-question at hand. Promptwatch's ChatGPT citation share by domain rank for August 2026 shows how loose the link to raw authority is: sites rated DR 46 to 75 earned 46% of ChatGPT citations, while the top DR 91 to 100 tier ended the month with about 3%, less than sites rated DR 0 to 15.
The more direct AI signal is usually the mention, not the link. When a respected publication names your brand in a category roundup, AI systems can pick up that association whether or not the article links to you. That is why link building and third-party mentions now overlap: the same PR, research and partnership work earns both.
The methods that earn useful backlinks have not changed much. Original research and data that journalists cite, free tools and calculators, detailed guides that become a reference for a topic, expert commentary for news stories, and case studies with real numbers all attract links without paying for them. Measure the result in the Links report in Google Search Console and in third-party link indexes, and for AI visibility track whether the pages and publications that link to you also show up as cited sources in your category. Our guide on how to grow citations in AI covers how link-worthy assets translate into AI citations.
Examples of Backlinks
- An HR software vendor publishes an annual salary survey of 3,000 respondents; trade press and two national newspapers link to it, and the survey page starts appearing as a cited source in ChatGPT answers about pay benchmarks.
- A cybersecurity firm builds a free password-strength checker that earns links from university IT pages and small-business blogs, which lifts the rankings of its paid product pages through internal links.
- A DTC brand discovers a cluster of paid links bought by a former agency, removes the ones it can, and documents the rest before a reconsideration request after a manual action in Search Console.
- A B2B company notices that a DR 65 industry blog linking to it is cited far more often in ChatGPT than a DR 92 news site that also links to it, and shifts PR effort toward specialist publications.
