What is a Backlink in SEO?
A clear guide to inbound links: what they are, how search engines use them, and how to build a profile that actually helps your rankings.
Definition
A backlink (also called an inbound link, incoming link, or external link) is a hyperlink on one website that points to a page on another website. When site A links to site B, that link is a backlink for site B.
Search engines treat backlinks as editorial endorsements - signals that another site considers your content useful enough to reference. This idea goes back to Google's original PageRank model: each page distributes a share of its authority to the pages it links to, and pages that earn links from many trusted sources tend to be seen as more credible.
Backlinks remain one of the strongest off-page ranking factors. Google has confirmed multiple times that links are still central to how it evaluates trust and relevance, even as algorithms have grown far more sophisticated.
How backlinks work for SEO
Search engines crawl the web by following links between pages. When they find links pointing to your site, they use that information in several ways:
- Discover and index your pages - Backlinks help crawlers find new or updated content. Pages with more quality inbound links are often discovered and indexed faster.
- Pass link equity - A link from a strong, trusted page can transfer part of that page's authority to yours. This is sometimes called "link juice" or PageRank flow.
- Signal topical relevance - When sites in your industry link to your content, it helps search engines understand what topics you cover and how you fit into the wider web.
- Improve rankings - Pages with strong, relevant backlink profiles tend to rank higher for competitive queries. Studies consistently show a strong correlation between quality backlinks and top search positions.
What makes a quality backlink?
Not all backlinks carry the same weight. Search engines evaluate each link based on several factors:
- Authority of the linking site - A link from an established, well-linked domain (such as a major publication or industry leader) typically carries more weight than one from a brand-new or low-trust site.
- Topical relevance - A link from a site in your niche is more valuable than one from an unrelated topic. A fitness blog linking to a health resource makes sense; a random directory on an unrelated subject does not.
- Anchor text - The clickable words in the link give context about the destination page. Natural, descriptive anchor text helps search engines understand what your page is about.
- Placement and context - A link embedded in the main body of a well-trafficked article is usually more valuable than one buried in a footer, sidebar, or page with no visitors.
- Editorial nature - Links earned because someone genuinely found your content useful are the gold standard. Google is skilled at detecting manipulative link schemes, paid link networks, and mass low-quality submissions.
The bottom line: one relevant link from a credible source often beats dozens of weak or spammy ones. Link quality correlates far more strongly with rankings than raw link count alone.
Types of backlinks and link attributes
Most links on the web are standard "dofollow" links by default - they can pass ranking signals to the destination. But HTML lets site owners add attributes that describe the nature of a link:
Dofollow (default)
Standard links without a restrictive rel attribute. They tell search engines the link is an endorsement and can pass link equity. These are the links you want for SEO.
Nofollow
Links with rel="nofollow". Used when you link to a page but do not want to imply a full endorsement. Since 2019, Google treats this as a hint rather than a strict rule, but it still generally does not pass the same ranking value as a standard link.
Sponsored
Links marked rel="sponsored" for ads, paid placements, or commercial agreements. Google recommends this over nofollow for paid links to stay within its guidelines.
UGC
Links with rel="ugc" (user-generated content), commonly applied to links in comments, forums, or other content submitted by visitors rather than the site owner.
Nofollow links can still send referral traffic when people click them. For SEO, however, focus on earning standard editorial links from pages that are relevant, trusted, and visible in search.
Why backlinks matter for your site
Better search rankings
Sites with strong backlink profiles consistently rank higher for competitive keywords. Backlinks are one of the hardest signals to fake at scale, which is why search engines still rely on them heavily.
Referral traffic
When someone clicks a backlink to your site, you get a visit from that referral. A well-placed link on a popular, relevant page can send a steady stream of visitors who are already interested in your topic.
Domain authority and brand trust
Backlinks from authoritative domains strengthen how trustworthy your site appears - both to search engines and to potential customers. That authority benefits your entire domain, not just the pages that receive links directly.
Long-term compounding value
Unlike paid ads that stop the moment you stop spending, a quality backlink can keep passing authority and sending traffic for months or years. Building links is slow, but the results tend to last.
How to get quality backlinks
The best backlinks are earned, not bought. Google penalizes manipulative link schemes, so focus on approaches that provide real value:
- • Create link-worthy content - Original research, in-depth guides, free tools, and data-driven articles naturally attract citations from bloggers, journalists, and industry sites.
- • Website directories - Listing your site in curated, relevant directories (like WebProjectList) can provide a legitimate dofollow backlink and extra visibility in your niche.
- • Guest posting - Contributing useful articles to respected sites in your industry often earns a contextual backlink in the author bio or within the content itself.
- • Digital PR and mentions - Press coverage, expert roundups, podcast appearances, and resource pages can generate strong editorial links from high-authority domains.
- • Broken link building - Find broken links on relevant sites and suggest your content as a replacement. You help the site owner fix a problem while earning a useful link.
- • Partnerships and community - Collaborating with complementary businesses, sponsoring events, or participating in industry communities can lead to natural link opportunities over time.
Avoid link farms, private blog networks (PBNs), mass comment spam, and paid link packages. These tactics may bring short-term gains but risk long-term penalties.
Our backlink requirement
To keep our directory valuable for everyone, we ask submitters on the Free plan to add a backlink to WebProjectList on their website - typically on the homepage. In return, you receive a dofollow backlink from our site to yours, which can strengthen your backlink profile and help search engines discover your content.
This mutual exchange helps maintain directory quality, keeps the platform sustainable, and gives both sides a genuine SEO benefit. You can use a simple text link or one of our optional badges. If you prefer not to place a backlink, our Premium plan is available as an alternative.
Frequently asked questions
A "backlink" is any link from another website that points to your site. You may also hear it called an inbound link, incoming link, or external link. A "normal" link can be outbound (you linking out) or inbound (someone linking to you). When we talk about backlinks for SEO, we mean inbound links to your site.
No. Quality and relevance matter far more than raw volume. A few editorial backlinks from trusted, topically related sites can outweigh dozens of links from low-quality or irrelevant pages. Search engines weight authority, relevance, and placement - not just the total count.
By default, most links are dofollow and can pass ranking signals to the destination page. Links marked with rel="nofollow", rel="sponsored", or rel="ugc" tell search engines the link should not be treated as a full editorial endorsement. Since 2019, Google treats these attributes as hints rather than strict rules, but for SEO you generally want standard dofollow links from relevant pages.
Yes, in some cases. Large numbers of spammy, paid, or irrelevant links can signal manipulation and may lead to ranking drops. Focus on earning links naturally from credible sources. If you have a history of toxic links, try to get them removed first, then consider Google's link spam guidelines and the Disavow Tool only as a last resort.
On your homepage (index page). Our system checks the main page of your website. The link must not use rel="nofollow", rel="sponsored", or rel="ugc". See our Backlink Resources page for HTML code and optional badges.
Ready to get your backlink?
Add your site to our directory and use our resources to add the required link.