What Is Link Building? A Beginner's Guide

Link building is the process of earning backlinks from other websites to your own. A backlink is a hyperlink on an external site that points to a page on your site. Search engines treat these links as signals of credibility and authority.

Link building is one of the most impactful things you can do for SEO. It is also one of the most misunderstood.

Why links matter

Google was built on the idea that links are votes. If a lot of trustworthy sites link to your page, Google infers that your page must be worth linking to. That inference feeds directly into rankings.

The relationship between backlinks and rankings has been studied extensively. Pages ranking in the top positions on Google consistently have more referring domains than pages further down the results. For competitive keywords, the difference can be enormous.

This does not mean that links are the only thing that matters. Technical SEO, content quality, and user experience all play a role. But for pages that are already technically sound and have good content, a lack of links is typically the main barrier to higher rankings.

The difference between links and referring domains

When people talk about link building, they often use "links" and "referring domains" interchangeably. They are not the same thing.

A backlink is a single link instance. If site A links to you from ten different pages, that is ten backlinks.

A referring domain is the unique website source. In the example above, that is one referring domain.

For most SEO purposes, referring domains is the more important metric. Getting ten links from one site is useful, but getting one link each from ten different sites is more valuable because it demonstrates broader trust across the web.

You can check your referring domain count and see where your links are coming from using Crawly's backlink checker.

What makes a good link?

Not all links are equal. The value a link passes depends on several factors:

Authority. A link from a major national publication or a well-established industry site carries far more weight than a link from a newly registered blog with no audience.

Relevance. A link from a site in the same industry or covering the same topic is more valuable than a link from an unrelated source. Google uses topical relevance as a signal of whether a link is natural and earned.

Placement. Links embedded in the body of an article carry more weight than links in footers, sidebars, or link lists. Editorial links, where the author chose to link to your content because it was useful, are the most valuable kind.

Anchor text. The visible text of a link gives Google a signal about what the linked page is about. A diverse, natural anchor text profile, with a mix of brand names, URLs, and occasional keyword phrases, looks more natural than one dominated by exact-match keywords.

Follow vs nofollow. A "followed" link passes PageRank. A rel="nofollow" link technically does not, though Google has said it treats nofollow as a hint rather than a directive. For link building purposes, aim for followed links, but do not dismiss nofollow links from high-traffic sites, as they still drive referral traffic and brand visibility.

Link building strategies that actually work

Creating linkable assets

The most sustainable link building strategy is creating content or tools that other people want to link to. This is sometimes called "earning" links rather than "building" them.

Linkable assets include:

• Original research and data. Journalists, bloggers, and other content creators need statistics to cite. If you publish original data, they will cite your source.
• Comprehensive guides. A truly exhaustive resource on a topic becomes the default reference for that subject. Other writers link to it because it saves them from having to explain the same thing in depth themselves.
• Free tools. Practical tools attract links from resource pages, roundups, and reviews. Crawly's backlink checker tool is an example of this approach.
• Unique frameworks or methodologies. If you develop a way of thinking about a problem that becomes widely adopted, people reference it with a link.

Digital PR and editorial coverage

Getting mentioned in online publications, news sites, and industry blogs builds high-quality referring domains quickly. This is known as digital PR.

Effective digital PR involves pitching original angles, data, or perspectives that a journalist or editor would find genuinely newsworthy or useful. It is not about submitting press releases to wire services and hoping for the best. It requires research, targeting the right publications, and crafting a pitch that gives an editor a specific reason to cover you.

Competitor gap analysis

If a site links to your competitors but not to you, it is already open to linking to content in your niche. Finding these gaps and pitching your own content or tools is one of the most efficient link building approaches available.

For a step-by-step guide to this process, see how to find and analyse competitor backlinks.

Broken link building

If a site links to a page that no longer exists, that link is wasted. Broken link building involves finding these dead links on relevant sites, identifying what the original content was about, and offering your own content as a replacement. A redirect checker is useful here for verifying whether a target URL is genuinely broken or simply redirecting somewhere unexpected.

This approach works because it presents the site owner with a clear, self-interested reason to act. You are helping them fix a problem on their site while earning a link in the process.

Guest posting

Writing articles for other publications in your industry can earn links back to your site. The value varies considerably depending on the publication's authority and how naturally the link fits the content.

Guest posting purely for link building, with little regard for the quality of the content or the relevance of the publication, is increasingly ineffective. Google has become better at identifying low-quality guest posts. The bar for this tactic to be worthwhile has risen substantially.

What to avoid

Some link building tactics that were effective in the past now carry significant risk:

• Buying links. Google's guidelines explicitly prohibit paying for links that pass PageRank. Sites caught doing this can receive a manual penalty. The risk is not worth the short-term gain.
• Private blog networks (PBNs). Networks of sites set up specifically to pass links to a target site. Google is effective at identifying these and devaluing or penalising them.
• Excessive link exchanges. Reciprocal link arrangements are natural in small quantities. Large-scale "I link to you, you link to me" schemes look manipulative.
• Keyword-stuffed anchor text. Building many links with identical, keyword-rich anchor text is a clear manipulation signal. Keep anchor text varied and natural.

Measuring link building progress

Track your link building efforts by monitoring referring domain growth over time. Use Crawly's backlink tool to check your domain monthly and record the referring domain count in a spreadsheet.

You should also track your rankings for target keywords. Referring domain growth and ranking improvements should correlate over time, though the relationship is not always immediate. Links take time to be discovered, crawled, and factored into rankings.

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Link building is a long-term investment. Done well, a strong backlink profile compounds over time, making it progressively easier to rank for new content and harder for competitors to close the gap.

The starting point is understanding your current profile. Run a backlink check on your site and your top competitors to see where you stand.