What Is Link Building in SEO? (And How It Actually Works)

If you’ve spent any time learning about Search Engine Optimization (SEO), you’ve inevitably heard the term “link building.” It’s spoken about as one of the most important and challenging parts of getting your website to rank higher on search engines.

But what is it, really?

Link building in SEO is simply the practice of getting other websites to link to yours so that search engines see your site as more trustworthy, relevant, and worth ranking.

Fair… But why do links still matter when Google talks so much about “helpful content,” and how do you build links without playing risky games with your domain?

Let’s break down what link building is, why it’s non-negotiable for SEO, the key terms you need to know, and the best “white-hat” strategies to start earning links today.

What is link building in SEO? (Definition)

Each link from another site to yours is called a backlink. When those links come from relevant, reputable sites, search engines treat them like votes of confidence that your content is worth showing to more people.

Basics of link building

Before we deep dive into link building, you need to understand the basic mechanics.

What is a link? (and why do they matter?)

There are three types of links you’ll encounter in SEO.

1. Backlinks (or inbound Links): This is the focus of link building. A hyperlink (backlink) is a link from another website to your website. This is the “vote of confidence” you want to earn.
2. External Links (or Outbound Links): These are links from your website to other websites. Linking out to relevant, authoritative sources is a good practice that shows Google you’ve done your research and are providing value to your user.
3. Internal Links: These are links from one page on your site to another page on your own site. Internal links are crucial for helping users and Google navigate your website and for spreading authority (or “link equity”) between your own pages.

You need all three. Internal links make the most of the authority you already have. Inbound links (backlinks) bring new authority in. Outbound links show you’ve done your research and are connecting readers to other credible sources, which is a positive signal for Google.

Key link building terms you must know

The world of link building has its own language. Here are the core terms you’ll hear.

Referring domain
A website that links to you. One domain can send you one backlink or hundreds.

**Anchor text
**This is the clickable, visible text of a hyperlink. For example, in the link learn more about SEO, the anchor text is “learn more about SEO.”

**Dofollow vs. Nofollow Links
**This is a crucial concept.

• Dofollow: By default, all links are “dofollow.” This tells Google to “follow” the link and pass authority (or “link juice”) to the destination page. These are the links you want.
• Nofollow (**rel="nofollow"**): This is a small piece of code added to a link to say you’d rather not vouch for the page it points to. Since 2019, Google has treated it as a hint rather than a strict rule, and it introduced two more specific values, sponsored (for paid links) and ugc (for comments and forum posts). See our guide to link rel attributes.

**Link Equity (or “Link Juice”)
**This is a simple analogy for the “power” or “authority” a link passes from one page to another. Think of it this way: a link from a major, trusted site like The New York Times has far more link equity than a link from a brand new, unknown blog.

**Domain Authority (DA) / Domain Rating (DR)
**These are third-party metrics (from companies like Moz and Ahrefs, not from Google) that estimate a website’s overall authority on a scale of 0-100. While not a direct ranking factor, DA/DR is a helpful shortcut to gauge the potential quality of a site you want a link from.

Where link building fits into SEO

Think of SEO as three big buckets:

• Technical SEO – can search engines crawl, index, and understand your site?
• On page SEO – is your content relevant, clear, and aligned with search intent?
• Off page SEO – do other websites trust you enough to link to you?

Link building lives in that third bucket.

Google says it uses links as a signal when determining the relevance of pages and to find new pages to crawl. In practice, links help in three ways:

1. Discover pages
   Crawlers follow links around the web. If nobody links to a page, it is harder to find and index.
2. Judge importance and authority
   If many reputable, relevant domains link to a page, it sends a strong signal that this page matters in its topic.
3. Understand context
   Anchor text and the paragraph around your link help search engines understand what your page is about.

So even if your content is solid, you are still competing with sites that have solid content and stronger link profiles. That is why so many brands eventually decide to invest in link building.

The data points the same way. Backlinko analyzed 11.8 million Google search results and found that the #1 result has, on average, 3.8x more backlinks than positions #2 through #10 (updated April 2025). That’s a correlation, not proof that links cause the ranking, but it shows why links matter. Google’s Gary Illyes put it well at PubCon in 2023: links are important, but people overestimate their importance, and it’s possible to rank without them.

How links are built in general

Natural links
These happen when you publish something useful or newsworthy, and people discover and link to it on their own. No direct outreach, no ask.

Built links
These are still editorial, but you did some work to make them happen. For example, you pitched a guest article, responded to a journalist, or showed a better resource to someone already linking to weaker content.

Self created links
These include most low quality profiles, comment links and forum signatures. They are easy to manipulate, so modern algorithms discount them heavily, especially at scale.

Modern link building focuses on natural and built links, not on dropping your URL into every directory you can find.

What makes a “good” SEO link?

Not every backlink is helpful. Some are neutral. Some are actively risky.

A strong SEO link usually checks most of these boxes.

1. Topical relevance

The linking website and the specific page should make sense for your topic.

If you run an SEO agency, a contextual mention on a serious digital marketing blog is far more useful than a random link from a coupon site. Relevance is a big part of link quality.

We unpack relevance, metrics, and risk in more detail in guide, understanding link quality and website metrics.

2. Real authority and trust

Authority is not just a DA or DR number. It looks like:

• A natural, healthy backlink profile of its own
• Real organic traffic across multiple pages
• Content that actual humans read and share

If a site is built only to sell links, and every article is a thin advertorial, its “authority” is fragile at best.

3. Organic traffic and visibility

The best backlinks can send real visitors, not just theoretical “link equity.”

If your link sits in a guide that ranks for relevant keywords and gets traffic, you win twice:

• You get a trusted citation in Google’s eyes.
• You also get referral traffic that can convert into leads or sales.

4. Contextual placement in the main content

Links in sidebars, author bios, or huge “partners” pages carry less weight.

Links that are integrated into the main body of an article, surrounded by text that explains why the link is there, usually carry more ranking power. These are called contextual links.

If you want to go deep into this specific angle, we have a full guide on contextual links and best practices coming from our campaigns.

5. Natural anchor text and patterns

Anchor text is the clickable part of the link.

A natural backlink profile usually includes:

• Brand anchors (your brand or domain)
• Descriptive phrases like “this internal linking guide”
• Partial match anchors with part of your keyword
• A few exact match anchors where it feels natural

Problems start when every link is an exact match money keyword. That pattern looks engineered rather than earned.

What makes a good SEO link

• Topical relevanceThe linking site and page fit your topic
• Real authority and trustA natural profile, real traffic, content people read
• Organic trafficThe link can send real visitors
• Contextual placementIn the main body, not a sidebar or author bio
• Natural anchor textA mix of brand, descriptive and partial match

Before you build links: fix your foundations

One thing we do on almost every campaign is a quick website audit before active link building starts.

During this audit you:

• Fix crawl and index issues that would waste link equity.
• Identify thin or outdated pages that need to be rewritten or expanded.
• Decide which pages actually deserve links and which should be merged or redirected.

Sometimes the best “link building” move is to turn a weak page into the strongest guide on the topic, then start outreach once it is genuinely worth linking to.

How you can build backlinks (white-hat strategies)

There are lots of fancy names for tactics. Underneath, most ethical white hat link building falls into a few simple patterns.

1. Create content that deserves links

The boring truth: link building becomes much easier when you have pages that deserve links.

Think about:

• In depth guides
• Original research, surveys or case studies
• Checklists, frameworks or templates that people keep referencing
• Useful resources for specific markets, industries or languages

Some formats are especially good at earning organic backlinks over time:

• Visual assets such as infographics, charts and diagrams
• Original data and industry benchmarks that others want to cite
• Simple tools or calculators that solve a small problem
• Comprehensive tutorials that people bookmark and keep revisiting
• Free resources like worksheets and templates

These pieces behave like link magnets. Outreach helps, but strong assets can attract backlinks for months or years.

Once you have your asset, you have to tell the world about it. “Build it and they will come” does not work in SEO. You must go out and get the links.

2. Guest articles and expert contributions

A classic way to earn backlinks. You provide genuinely useful content to another site’s audience and, in return, earn a relevant, contextual link in your byline or within the article.

Don’t do it just for the link. Focus on high-authority, relevant sites in your niche. Write your absolute best content, and aim to provide genuine value to their audience.

3. Link insertions (niche edits)

Instead of writing a full article, you get your link added into an existing relevant article.

This works well when:

• The article is already getting traffic
• Your page genuinely adds value as a resource or example

For example, if a blog has a guide about “remote team management” and you have a strong article or product that fits into that topic, your link can be added as a recommended resource.

4. Digital PR & partnerships

Think beyond classic “SEO blogs”:

• Collaborate on webinars, reports, or joint guides with partners
• Pitch newsworthy stories or data to journalists and industry publishers
• Sponsor or support relevant community projects where a mention makes sense

These links are harder to get but often become your most valuable assets.

Some other common link building tactics you will see

Alongside classic guest posting and manual outreach, most campaigns draw from a handful of proven tactics:

• Skyscraper content – create the most complete, useful piece on a topic, then show it to sites that currently link to weaker resources
• Resource page outreach – find “resources” or “recommended tools” pages and ask to be included where relevant
• Broken link building – find dead resources with many backlinks, publish a better replacement on your site, then notify those sites
• Image link reclamation – track where your images or graphics are used without credit and politely ask for a backlink
• Unlinked brand mentions – turn existing brand mentions into backlinks with a simple, low friction request

You do not need to use every tactic at once. The right mix depends on your niche, your resources and how strong your current content is.

Risky link building practices to avoid

Now the other side of the story. Some tactics might still work in the short term, and some quietly push you toward a manual action or just burn budget. Google’s spam policies (updated August 2026) list several of them as link spam: buying or selling links for ranking purposes, excessive link exchanges, automated link creation, low-quality directory links, widely distributed footer or widget links, and forum comments with optimized links. Watch out for these.

1. Cheap, obvious paid links

Offers that promise dozens or hundreds of high DA links for a tiny fee usually rely on low quality networks. They often leave clear footprints that can be picked up by spam systems.

We go into the nuance of when paying publishers makes sense, and when it does not, in our guide on buying backlinks.

2. PBNs and fake “networks”

Expired domains rebuilt into look-alike blogs with generic content and no real brand. These are clusters of sites created mainly to pass link equity. They usually look fine on the surface but share patterns in ownership, hosting, templates or interlinking that make them risky long term.

3. Over-optimized anchor text

If most of your backlinks use the same exact money keyword, it is not a natural pattern.

Healthy sites tend to attract a mix of branded, partial match and generic anchors, simply because different authors describe them in different ways.

4. Mass link exchange

Slack/FB “you link to me, I link to you” groups, link wheels, and partner pages created only for cross-linking. Google’s spam policies explicitly call out excessive link exchanges.

5. Comment, forum & profile spam

Automated comments, empty forum profiles, and random signature links. They’re usually nofollow, send no real traffic, and make your promotion footprint look spammy.

6. Junk directories & citation blasts

Hundreds of “SEO directories” with zero editorial review or real users. They clutter your link graph without adding trust or relevance.

7. Thin, auto-generated content for links

AI/spun articles published in bulk across weak sites just to host outbound links. No real readership, no value – and increasingly easy for Google to ignore or downrank.

8. Sitewide footer/widget links

Followed “SEO by X” links in thousands of footers or widgets. Non-editorial, sitewide, commercial anchors are classic manipulation signals.

9. Off-topic links

Links from totally unrelated niches (e.g., crypto blog linking to a dentist). A pattern of irrelevant links screams “paid” rather than earned.

How to measure if your link building is working

How do you know if all this hard work is actually paying off? Don’t just count the number of links. Focus on these key metrics.

1. Number of referring domains and backlink quality over time

Are you attracting more unique domains that are relevant and healthy, not just more links?  You want to get more links from more unique, high-quality websites.

2. Organic traffic to target pages

Watch how search traffic evolves on the pages you are actively supporting with backlinks. It rarely moves in a straight line, but you want to see a clear upward trend over months, not days.

3. Rankings for your main keywords

Are your target pages (the ones you’re building links to) climbing up the search results for their target keywords? Rank trackers help, but even Search Console can give you a decent picture.

4. Leads, sales or other conversions

Ultimately, link building should support business outcomes. You should have started getting more business from organic search than before.

5. Domain authority/rating (DA/DR)

You can also keep an eye on third-party authority metrics like DA/DR; they’re not ranking factors, but they often tick up as you earn high-quality links.

If you are not sure how to connect backlinks to results, our guide on how to measure the success of a link building campaign walks through a simple framework.

When should you do link building yourself vs get help?

Most teams start link building in house. You write a few guest posts, send some outreach emails, land a couple of backlinks and it feels manageable.

It usually gets hard when you need link building to be consistent, not just “whenever we find time.”

Here are clear signs it might be better to bring in specialist help:

• You need steady volume, not one offs
  A competitive niche often needs a predictable stream of vetted opportunities each month. That’s tough to maintain on the side of someone’s main role.
• Your team is already stretched
  If link building keeps getting pushed to “next month,” it probably needs its own owner – either an internal specialist or an external partner.
• You’re expanding into new markets
  New countries and languages mean new publishers, norms and expectations. Trying to handle several markets with a small in-house team can dilute quality quickly.
• You want stricter quality control
  At some point, “any decent DR site” isn’t enough. You care about topical fit, traffic quality and editorial standards – which takes time and experience to vet properly.

If you need consistent, vetted backlinks in multiple markets, let’s talk. Share your site, target countries and priorities, and we’ll come back with a clear, practical approach to take the burden off your shoulders.

FAQs: What people also ask about link building

Is link building still relevant for SEO today?

Yes, with caveats. Helpful, high-quality content comes first. In competitive spaces, links still help, and Google’s own documentation says it uses links as a signal. But Google’s systems have moved from counting links to judging their quality and relevance, and Google has said links are overestimated in importance.

Can I rank without building links?

Sometimes. For very low-competition, long-tail keywords with little competing content, yes. Ahrefs found that about 20 million pages in its index have no referring domains at all, yet a small number still get over 1,000 visits a month, typically on low-competition topics on established sites.

For valuable, competitive topics, it is rare to rank well in a sustainable way without earning links, even if you never run “active link building campaigns” and instead rely on strong content and brand marketing.

How many backlinks do I need?

There is no magic number.

A better approach is to:

• Analyze the top 5–10 ranking pages for your target keyword
• Look at how many quality referring domains they have
• Aim to build a similar or slightly stronger quality profile over time

What is the future of link building in an AI first world?

Nobody can promise that a link will get you cited by an AI tool. Ahrefs studied 75,000 brands in December 2025 and found that brand mentions across the web correlate with visibility in AI Overviews (0.656), ChatGPT (0.664) and AI Mode (0.709), and that link and content volume had little impact on AI visibility. Google itself says there are no special optimizations needed to appear in its AI features. So the practical advice is the same: earn mentions and links on relevant, trusted sites, and make your own pages worth citing.

If you want a deeper, more strategic view, read our full guide on the future of link building in an AI-first world.

Last but not least

Link building is no longer about tricking Google. It’s about earning trust.

At its best, link building is the process of building a strong brand, creating content that is genuinely valuable, and fostering real, human relationships within your industry. It’s a marathon, not a sprint. Focus on quality over quantity, be patient, and aim to create a website that people want to reference and link to. That’s the real secret to sustainable, long-term SEO success.

Sources

Checked on 30 September 2026.

• Google Search Central: Link best practices for Google (updated December 2025)
• Google Search Central: Spam policies for Google web search (updated August 2026)
• Google Search Central: Qualify your outbound links to Google (updated December 2025)
• Google Search Central: AI features and your website (updated December 2025)
• Backlinko: We analyzed 11.8 million Google search results (updated April 2025)
• Search Engine Roundtable: Google says links are no longer a top three ranking factor (PubCon, September 2023)
• Ahrefs: 96.55% of content gets no traffic from Google (December 2023)
• Ahrefs: Brand visibility in AI systems (December 2025)