Backlink: the precise definition
A backlink is a hyperlink located on a third-party site that points to a page on yours. It is also called an incoming link, a return link or, in technical terms, an inbound link. It is the basic unit of link building.
The concept goes back to PageRank, Google's founding algorithm. The idea is simple: if site A cites site B with a link, A grants a form of trust to B. Each link therefore works like a vote. The more votes a page receives from credible sources, the more legitimate search engines consider it on its topic.
A backlink is made up of three elements: the source page (the site that places the link), the anchor (the clickable text) and the destination page. The anchor conveys semantic context: a link anchored on "SEO agency" tells search engines the subject of the target page. This is why an SEO agency works as much on the nature of links as on their anchor text.
The types of backlinks
Not all backlinks are alike. Their value depends first on their technical nature and their origin.
Dofollow and nofollow
A dofollow link passes authority to the target page: this is the default behavior. A nofollow link carries the rel="nofollow" attribute, which tells search engines not to fully pass on that authority. Since 2019, Google has treated nofollow as a hint rather than an absolute directive. Google added two complementary attributes: sponsored for paid or affiliate links, and ugc for user-generated content (forums, comments).
Editorial, manual and toxic links
The editorial link is the most valuable: a site freely chooses to cite you because your content deserves it. The manual link is obtained through an active effort (press relations, partnership, guest post). Finally, some links are harmful: spam directories, link farms, artificial networks of sites. These toxic links can trigger a penalty. Knowing how to identify and disavow them is a project in its own right, detailed in our guide on toxic backlinks.
| Criterion | Editorial dofollow link | Generic purchased link |
|---|---|---|
| Authority transfer | Strong | Weak or none |
| Penalty risk | Very low | High |
| Topical relevance | Naturally aligned | Often absent |
| Effect on the brand | Real awareness | None |
| Durability | Stable over time | Volatile |
What makes a good link
A good backlink combines three qualities: relevance, authority and naturalness. A single link from a reference media outlet is often worth more than fifty links from unrelated sites.
Topical relevance comes first. A link from a legal website to a law firm sends a coherent signal. The same link to a shoe e-commerce store makes no sense to search engines. The authority of the source page also matters: a link from a page that is itself well linked passes on more value. The naturalness of the overall profile, finally, protects you from suspicion: a healthy profile mixes dofollow and nofollow, brand anchors, exact-match anchors and generic anchors.
Does the referring site cover a subject close to yours? If not, the link adds little, or even a risk.
Look at the organic traffic and the inbound links of the source page, not just a third-party indicator like Domain Rating.
A link inserted within an editorial paragraph is worth more than an isolated link in the footer.
A profile saturated with exact-match anchors signals manipulation. Vary them: brand, bare URL, natural phrases.
A reference piece of content, an original study or a press relationship generates durable and legitimate links.
This is precisely the logic of digital PR, where the quality of the publications obtained determines the value of the links. We develop this approach in our dedicated article on digital PR in SEO.
The role of backlinks in SEO
Backlinks remain one of Google's most decisive ranking factors. They feed the assessment of a domain's authority and condition a page's ability to rank for competitive queries.
In concrete terms, a strong link profile produces three effects. It accelerates indexing: crawlers discover your pages faster when they are linked from frequently crawled sites. It strengthens rankings on target phrases, especially when anchors and contexts are coherent. Finally, it brings direct referral traffic: a reader who clicks on a link lands on your site without going through a search engine.
This importance is not declining, but it is becoming more nuanced. Google increasingly evaluates contextual quality rather than volume. A link from a page that is genuinely read, on a site that is authoritative in your field, carries more weight than an accumulation of weak links.
AI Overviews citations come from the organic top 10. A strong link profile, by pushing your pages into that top 10, therefore also conditions your presence in AI-generated answers.
Backlinks and GEO: the nuance of mentions
In the era of answer engines, the backlink does not disappear, but it shares the stage with a new signal: the brand mention. LLMs like ChatGPT, Perplexity or Gemini do not follow links the way Google does. They reason on language and on what is said about you, everywhere on the web.
An Ahrefs analysis covering 200,000 domains, published in December 2025, illustrates this shift. Off-site brand mentions correlate more strongly with AI citations (YouTube 0.737, and 47.9% of ChatGPT citations come from Reddit or Wikipedia pages) than domain authority, whose correlation remains weak (0.266). In other words, being cited, named, discussed sometimes counts more than a classic dofollow link.
The consequence is strategic. An unlinked mention, long considered a half-success in SEO, becomes a top-tier asset for AI visibility. The work of press relations and presence on high-authority platforms now serves two goals: feeding your link profile and building your reputation with the models. With more than 900 million weekly users on ChatGPT, ignoring this second channel would be a mistake.
To assess where you stand on these two fronts, our 40-point Checklist details the concrete criteria that make the difference between a site that is merely indexed and a site that is genuinely cited.
Request your free GEO audit: we analyze your link profile and your brand mentions to reveal your levers for citation by ChatGPT, Perplexity and Gemini.
Questions fréquentes
How many backlinks do you need to rank well?+
There is no universal threshold. The number depends on the competition for your target query. On a low-competition keyword, a few quality links are enough. In a contested market, it is the relevance and authority of the referring domains that make the difference, not the raw volume.
Does a nofollow backlink have any value?+
Yes. Since 2019, Google has treated the nofollow attribute as a hint rather than a strict directive. A nofollow link from a recognized media outlet drives traffic, builds brand awareness and contributes to a natural link profile. It does not pass authority the same way a dofollow link does, but it counts.
Is buying backlinks dangerous?+
Yes, buying links violates Google's guidelines and exposes you to a manual or algorithmic penalty. Paid links that are not flagged with a sponsored attribute are the leading source of toxic profiles. Favor links earned through content, press relations or editorial partnerships.
Do backlinks count for ChatGPT and AI models?+
Indirectly. LLMs do not follow links the way Google does. An Ahrefs analysis from December 2025 shows that off-site brand mentions correlate more strongly with AI citations than domain authority does. A strong link profile helps your organic ranking, which feeds answer engines, but the mention itself becomes the key signal.
