Link Building for SEO: A Guide to the Basics

Rachel Handley

Apr 25, 202416 min read
Contributors: Carlos Silva, Christine Skopec, and Zach Paruch
Link Building
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Learn why you should enhance your search engine optimization (SEO) strategy with link building. And how to do it.

Link building is an SEO tactic that involves getting other websites to link to your website. So search engines like Google may view it as more authoritative and rank it higher in unpaid search results.

Basically, Google treats certain kinds of links from other sites (backlinks) like endorsements. The higher the quality and quantity of backlinks pointing to your site, the more trustworthy it can seem.

Arrows representing backlinks point from “external websites” to “your website”

For example, Semrush’s Backlink Analytics tool shows that bbc.co.uk has backlinks from over 1 million domains. Including reputable sites like cdc.gov, microsoft.com, and britannica.com.

BBC has 1.3 million referring domains

Google’s search algorithm takes this strong backlink profile into account when determining whether and how high to include bbc.co.uk in relevant search results. And it’s likely to rank the site well as a result.

Of course, there are lots of other ranking factors that Google considers. But 8 of the top 20 relate to backlinks, according to our study.

It’s possible to acquire backlinks naturally over time. But proactively building links can help you to gain or maintain a competitive edge in search.

As long as they’re the right kinds of links.

What Affects a Backlink’s Value?

Some backlinks are more valuable for your SEO than others. Some don’t have any effect at all. And ones acquired using spammy practices (sometimes known as toxic backlinks) can be harmful. 

Here are the main factors to consider when backlink building:

Authority

Generally, the more authoritative the referring (linking) site, the more valuable the backlink.

For example, a backlink from bbc.co.uk will likely have a much bigger impact on your SEO than one from an unknown blogger.

Semrush measures site authoritativeness with a metric called Authority Score—which is on a scale out of 100. It considers three main factors:

  • Link power: The quality and quantity of backlinks to the site
  • Organic traffic: The estimated number of unpaid search engine visits the site gets each month
  • Natural profile: How natural (i.e., not spammy) the site’s backlink profile appears to be

If you use the Link Building Tool to find sites that might link to you when asked, you can review their Authority Scores in the “AS” column.

AS column for domains like domain and apartmentlist

But don’t worry about accumulating backlinks from sites with less authority. Those fit fine within a balanced backlink profile. 

As the BBC’s profile shows, it’s normal to have more backlinks from low-authority sites and fewer from high-authority sites.

Referring domains by authority score graph shows BBC mostly has referring domains with a score of 0-10

Relevance

It’s usually better to build SEO links from sites that are highly related to your own. Because it suggests you’re well-respected by experts in the field.

It’s also better if a backlink appears within highly relevant content. 

Let’s say you have three backlinks to your basketball shoes range:

  • Backlink 1 appears on a gardening website in an article about growing plants. It’s unlikely to carry much SEO weight (if any), because the site and topic are so unrelated to you. 
  • Backlink 2 appears on a sports blog in a post about cardiovascular exercise. This could carry some SEO weight because the site shares your niche.
  • Backlink 3 appears on a sports blog in a basketball shoes buying guide. This could carry a good amount of SEO weight, because it suggests your page is highly relevant to the topic at hand. And that the link is genuinely useful to readers.

The more prominent the backlink is on the page, the more valuable it can be for SEO.

This is because Google may consider the likelihood that a reader will click on a link based on where it’s located. This is called the “reasonable surfer model,” and it’s described in this patent.

For example, links that are in sidebars, in footers, and low on a page’s content may not be worth as much as those higher in the page’s body. 

Generally, it’s best if your backlink appears early on in the main body content.

Like this:

A backlink in a paragraph of a blog post

Anchor Text

Backlinks with descriptive anchor text (the clickable, linked text) can be better for SEO.

In a blog post about how to make a latte, the phrase chocolate syrup is hyperlinked

That’s because search engines use anchor text to better understand what the linked page is about. And by extension:

  • How the linked page relates to the referring page
  • What kinds of keywords (search terms) the linked page should possibly rank for

For example, a backlink with the anchor text “basketball shoes” clearly indicates what the linked page is about. Whereas generic anchor text like “click here” gives no useful context.

That said, it’s important that anchor text reads naturally.

If you focus too much on optimizing anchor text for search engines—not users—Google may consider your site to be engaging in spammy link building practices. 

And that can lead to a Google penalty that harms your search performance.

You can check your backlink anchor text with the Backlink Analytics tool.

Just enter your domain and go to the “Anchors” report.

BBC anchors report shows anchor text copy

Nofollow, Sponsored, and UGC Attributes 

Some links contain a nofollow attribute (or another attribute) that tells Google not to pass ranking strength to the linked page. 

Here’s a quick overview of those attributes:

Link Attribute

Description

rel=”nofollow”

Used to identify links that the publisher doesn’t want to endorse. Google is likely to respect the publisher’s wishes.

rel=”sponsored”

Used to identify links that were paid for by the linked site. Google ignores these links because they aren’t genuine endorsements.

rel=”ugc”

Used to identify links that were placed by users (e.g., in comments sections). Google ignores them because they’re too easy to manipulate.

While they may drive brand awareness and referral traffic, these kinds of backlinks are unlikely to help your rankings.

In HTML, a link with the nofollow attribute (a “nofollow link”) looks something like this:

<a href="https://example.com" rel="nofollow">Anchor Text</a>

But the link looks normal on the page.

Standard links that don’t contain a nofollow, sponsored, or UGC attribute are sometimes called follow links or dofollow links. These are the ones you want when building links for SEO.

You can see any site’s ratio of nofollow to follow links with the Backlink Analytics tool.

Just scroll to the “Link Attributes” chart in the “Overview” report:

Link attributes graph shows mostly follow links with some nofollow, sponsored, and user generated content links

Below, you’ll learn about the four fundamental ways to build links. Some of which work much better than others.

After that, we’ll share nine specific tactics you can use in your strategy.

When you earn links, other websites link to yours without you asking them to. 

This can be extremely cost-effective. Plus, you don’t need to worry about the links violating Google’s link spam guidelines because you aren’t responsible for creating them.

The best way to earn links is to create high-quality content that people want to link to—i.e., link bait.

Here are a few different types of content people tend to link to:

  • Visual assets (infographics, charts, diagrams, etc.)
  • Original research and data (industry studies, surveys, proprietary research, etc.)
  • Online tools and calculators
  • In-depth guides and tutorials

To see which pages get the most backlinks on your own or a competitor’s site, enter the domain into the Backlink Analytics tool.

Then, head to the “Indexed Pages” report.

The “Domains” column shows how many different sites link to the page in the corresponding row.

title, url, and domains columns highlighted

You can click the icon in the “Title and URL” column to see the content for yourself.

And click the link in the “Domains” column to see where all the page’s backlinks come from.

Open URL icon highlighted beside url and domains number highlighted

Asking for links is when you actively contact a person (or team) and persuade them to link from their website to yours.

There are two main reasons why they might link to you:

  • There’s something on your website that their audience will be interested in
  • To credit you where you’re mentioned in their content

Semrush’s Link Building Tool finds high-quality prospects (sites that might link to you) by looking at your competitors and the keywords you want to rank for.

After setting up your project, head to the “Prospects” report to see a list of suggested websites.

prospects tab shows 994 domains for backlink opportunities

You can then choose which opportunities to pursue. And use the tool to manage the entire process of quality link building.

Going to another website and manually adding your link there isn’t a good way to build backlinks. Because Google doesn’t want to count links that you have (or might have) placed yourself. 

That includes links added to:

  • Social media profiles
  • Business directories
  • Forums, communities, and Q&A sites (like Quora)
  • Blog comments
  • User profile pages

You can still add links in these places. To help drive referral traffic to your website.

But only include them where they create genuine value for users. And not in an effort to generate SEO value.

Otherwise, you may be engaging in link spam and harming your brand image.

You should not buy SEO links that are intended to influence your rankings.

In other words, you should only pay for backlinks if they’re qualified with the rel=”sponsored” or rel=”nofollow” attribute. (Which tells search engines to ignore them.)

If a paid link is not qualified:

  • The link violates Google’s link spam guidelines and both sites risk being penalized
  • Google is likely to recognize that the link is paid for and ignore it anyway

To clarify, you can pay for link building services from a freelancer or agency. But the sites hosting your backlinks shouldn’t receive any form of payment. This includes money, products, services, etc.

There are many strategies for building links. But here are nine of the most effective options. 

1. Conduct Email Outreach

Email outreach is the process of reaching out to a website (or website representative) to persuade them to give you a backlink.

It’s important because people can’t link to your content without discovering it. Even the best assets need to be promoted to attract links. 

To find prospects to reach out to, use Semrush’s Link Building Tool

Open the tool and click “+ Create project.”

create project button in link building tool

Then, enter your domain, give your project a name, and click “Create project.”

enter the domain and give the project a name in link building tool

Next, add the keywords you want to rank higher. These keywords should be related to the page(s) you’re trying to build links for. 

adding bed and breakfast keyword to Keyword Magic Tool

After you’ve added your keywords, click on “Competitors” at the bottom of the pop-up.

competitors button

Now, add the competitors you want to outperform. 

And when you’re done, click “Start Link Building.” 

start link building button highlighted

After the tool has analyzed the data, click on “View prospects” to see everyone you can reach out to for backlinks. 

a list of domain prospects, showing 1312 results

You can reject the prospects you don’t want to reach out to from this screen. Like if the site isn’t relevant. Or you don’t want a link from that website.

To reject a prospect, click on the trash can icon. 

Like so:

Trash can icon next to the To In Progress button

For prospects you do want to reach out to, click the “To In Progress” button, and they’ll be added to the “In Progress” tab. 

To In Progress button highlighted

From the “In Progress” tab, you can contact any prospect via a connected email account. 

Simply click on the “Contact” button. 

The screen will expand to show an email template with default information. 

Like this:

email draft to request backlink

Now, customize your emails to make your pitch specific to the prospect. 

After you’ve sent your emails, the “Status” column shows whether your email was sent, received, opened, or replied to. 

And you can click the check mark in the “Actions” column after you receive a backlink. 

status column showing that the backlink has been earned

2. Become a Source

If you work with reporters to provide information or assets, you may receive a backlink by way of attribution.

You can find these requests through services like Connectively (formerly known as HARO/Help a Reporter Out). They look something like this:

Connectively request for experts in influencer marketing

Just search for requests that are relevant to your expertise. Then, send a pitch to the reporter through the platform.

You can also find requests by browsing hashtags like #JournoRequest on X (formerly Twitter).

post on domain or x requesting gift ideas for mother's day gift guide with hashtag journorequest

That can help you end up with backlinks like this one:

backlink to an illustrator in the mother's day gift ideas guide

Broken link building is the process of finding backlinks that no longer work and persuading the publishers to replace them with working links to your site.

It’s an effective tactic because no one wants to send visitors to broken pages. And you’re offering a convenient solution. 

You can find competitors’ broken backlinks with Semrush’s Backlink Analytics tool.

Enter a competitor’s domain and click “Analyze.” 

search chewy.com in backlink analytics tool

Then, head over to the “Indexed Pages” report and check the box next to “Broken Pages.”

Like this:

broken pages box in backlink analytics tool

You’ll see a list of broken pages on the competitor’s site. Sorted by the number of “Domains” (how many different sites link to them). 

domains column highlighted in the indexed pages report

Starting at the top, look for a broken page that you have a good alternative for.

(You may need to put the URL into the Wayback Machine to see what it used to look like.)

When you find one, click the number in the “Backlinks” column to see all the page’s backlinks.

Backlinks number highlighted, in this case there are 832 backlinks to this broken page

These are the backlinks you may be able to inherit. Sorted according to “Page AS” (the page’s authority score).

Starting at the top, look for backlinks you want to try to inherit. 

You can click the icon alongside the URL to view the backlink in context. And see if it’ll be a good fit for your proposed link.

Open url button highlighted

If you want to pursue an opportunity, find the email address for the appropriate contact. And send them your proposal.

Then, repeat this process as many times as you’d like.

4. Create Linkable Assets

A linkable asset is a piece of content that has good potential to earn backlinks naturally. Such as a tool, research report, or in-depth guide.

For example, Semrush’s blog post on content marketing statistics has backlinks from over 2.5K domains.

semrush content piece has 2.9k referring domains

This is because it’s a useful source to cite when writing about the importance of content marketing.

Here’s what our backlink from Adobe to that post looks like in context:

Adobe cites Semrush blog and includes link to study

5. Find Unlinked Brand Mentions 

An unlinked brand mention is when a website mentions you or your business without linking to you. 

Like this:

Backlinko includes Semrush name in content but does not link to Semrush

With a gentle nudge, many site owners are happy to turn your unlinked mention into a link. 

To quickly find unlinked mentions, use the Brand Monitoring app.

After signing up, create a “New query.”

new query button in Brand Monitoring app

Then, choose “Brand.”

brand option selected in Brand Monitoring app

You’ll see a pop-up like the one below. And for the best results, you should fill out all the sections.

Pay particular attention to:

  • Monitor this brand: This is where you should add your brand name and any variants. So the tool knows what text to look out for.
  • Track backlinks: This is where you should add your domain. So the tool knows whether you received a backlink.
create bran query window in Brand Monitoring app

When you’re done, click “Create query.”

You can then see a list of all the mentions found.

In the left-hand menu, go to “Mention details” > “Backlinks” and select the circle next to “Without backlinks” to focus on your unlinked brand mentions.

filtering unlinked bran mentions in Brand Monitoring app

For every unlinked mention you find, consider reaching out to the page’s owner or author to kindly request a backlink. 

Analyzing competitor backlinks helps you to replicate link building tactics that work for your rivals. 

And it can tell you:

  • Which types of content tend to earn the most backlinks
  • Who’s linking to others in your niche

To start, go to Semrush’s Backlink Analytics tool. 

Enter a competitor’s domain. Then, go to the “Indexed Pages” tab. 

This report shows a table with all of your competitor’s pages sorted by number of referring domains.

a table showing competitor’s pages sorted by number of referring domains

Click through to the top-performing pages. And look for patterns in topics, style, length, and format. 

For example, let’s say your competitor’s most-linked pages all contain videos.

You might then decide to incorporate video into your content marketing strategy. And emphasize the quality of your videos when reaching out to backlink prospects.

Recovering backlinks that you lost (which can happen if the linking site updated the content, deleted the page, or redirected the page) is often easier than building links from scratch. Because the site was already willing to link to you in the first place.

To easily find lost links, head over to Semrush’s Backlink Audit tool.

And after setting it up, go to the “Lost & Found” tab. 

“Lost & Found” tab in Backlink Audit tool

This report shows how many referring domains have been acquired, broken, or lost over the past 90 days. 

a report showing new, broken, and lost domains

In this case, we’re only interested in lost backlinks. 

So, scroll down and click on the “Lost” box at the top of the list. 

“Lost” box highlighted at the top of the list

These are all the domains you’ve lost backlinks from within the past three months. 

To help prioritize, filter the list to show follow links with low toxicity scores (these tend to be high-authority sites). 

Like so:

filtering the list to show follow links with low toxicity scores

Next, visit each URL and try to work out why you lost the backlink.

  • If the page was removed, search the site to see if they published a replacement
  • If the page was redirected, see whether there’s a good spot for your link on the new page
  • If the page was updated, see whether there’s still a good spot for your link

If you’re able to find a relevant place for your link, consider reaching out.

Politely ask if there’s a specific reason that they removed your link (this is a great ice-breaker). Then, explain why you think the link would still be a useful addition to their content.

Hopefully, you’ll end up recovering your link. Or getting some useful feedback.

A backlink gap analysis reveals websites linking to your competitors but not to you. 

If a site links to a competitor, they might be willing to link to you, too. Especially if you create superior content.

To start, open up Semrush’s Backlink Gap tool. 

Add your domain and your competitors’ domains. And click “Find prospects.”

enter yours and competitor's domain in Backlink Gap tool.search

The “Best” tab shows domains that link to all your competitors but not to you.

So, these are the strongest backlink prospects.

a table showing domains that link to all your competitors but not to you

The column under every competitor’s domain shows how many backlinks they have on each site.

Click the arrow next to one of those numbers to see details about the backlinks from a particular domain. Including the anchor text and target URL.

opened details about the backlinks from amazon.com domain, showing anchor text, and target url

Check the boxes next to all the domains you want to contact.

Then, click “+ Start Outreach” to send them to the Link Building Tool.

“+ Start Outreach” button in Link Building Tool

From there, you can manage the rest of the link building process.

9. Digital PR

Digital PR is the process of gaining online coverage for your brand. While becoming a source can fall under this tactic, it more typically involves creating an interesting story and then sharing it with relevant reporters via a press release.

Reporters who cover your story may credit you with a link to your site.

For example, holiday park operator Parkdean Resorts created a mini holiday park for hedgehogs. And tied it to a news story about hedgehogs becoming endangered.

They gained press coverage (and backlinks) on several sites. Including Lonely Planet: 

Press coverage gives backlink

We recommend running monthly (or more frequent) link building audits. To keep track of earned links, lost links, and overall backlink quality. 

Use Semrush’s Backlink Audit tool to do this. 

After setting up the tool, click the settings icon in the upper right.

settings icon in the upper right corner of Backlink Audit tool

Then, click “Recrawl schedule.”

recrawl schedule option in Backlink Audit tool

Select “Once a month” in the drop-down menu. And check the box next to “Send an email every time an audit is complete.” 

recrawl settings set to once a month in Backlink Audit tool

Then, click “Update.”

"Update" button

You’ll now receive monthly alerts about your latest audits.

In the “Overview” part of your audit, you can learn about potential issues. (Such as backlinks you’ve lost. Or links to broken pages on your site.) And get help fixing them.

Plus, you can monitor your site’s Authority Score. 

This should increase as your backlink profile strengthens. But bear in mind that even small increases can represent a lot of work and links.

Authority Score and alerts section highlighted in the Overview report

With Semrush’s link building tools, you can get the insights and support you need to acquire quality backlinks. And improve your SEO results.

  • Link Building Tool: Identify relevant prospects and streamline the outreach process
  • Backlink Analytics: Analyze competitors’ backlink profiles
  • Backlink Gap: Find domains that link to your competitors but not to you
  • Backlink Audit: Monitor your link building results and identify potentially harmful backlinks
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