The Definitive Guide to Link Building: Dos, Don’ts, and Best Tools

Link building is one of the most important parts of SEO and digital marketing. Unfortunately, it’s also difficult, a little boring, and can feel very aggressive.

Don’t worry. We all deal with it, and it doesn’t have to feel icky.

To make things easier, I compiled a list of dos and don’ts for link building — and other helpful information that takes some of the difficulty and boredom out of link building.

We may earn a small commission from purchases made via links on this page. It doesn’t cost you anything extra, but it allows us to keep creating great content.

What is link building? Link building is the process of obtaining backlinks (one-way hyperlinks) from various sources with the intention of improving search engine ranking and increasing organic traffic.

Link building is critical to SEO because the number of links pointing to a web page is one of the main ways that Google measures whether and how high your page should rank in search results.

The most valuable backlinks are from high-authority websites or hyper-relevant websites:

  • High-authority: A backlink from The New York Times website is great for just about any website.
  • Hyper-relevant: If you’re a trucking company, and a diesel engine company links to your site, that’s great.

Link building is all really about relationship building. Not that fake, self-serving networking-type business — people can smell that from a mile away.

The best backlink building practices require time to build meaningful relationships with other websites, journalists, peers in your field, etc.

Ideally, people should eventually be linking to your site without you even asking. That can take a long time and effort, but it is possible.

In the meantime, figure out the best link building strategy for your website or client, then implement it to the best of your ability.

A link has 5 parts:

  1. Opening tag: <a
  2. The actual destination: href=“”>
  3. Optional rel attributes: rel=“nofollow
  4. Anchor text, AKA the “clickable” part: this link site
  5. Closing tag: </a>

<a href=”” rel=”nofollow”>this link site</a>

In other words, a link has 3 parts in between the opening and closing tags: optional attributes, the destination URL, and the clickable anchor text.

The different parts of a link are usually not visible. However, most editors can obtain access to the code of any given page or post on a website. On WordPress, for example, you’re able to insert shortcode anywhere you like within a post.

The rel attribute (rel tag) is the part of the link that is unseen to the casual reader but that Google bots use to understand the relationship between the link and the host site.

4 Rel Tags You Should Know

The 4 outbound link rel attributes you need to know:

  • Dofollow
  • Nofollow
  • UGC
  • Sponsored


The dofollow rel tag tells Google that you are fine passing authority along to the linked site in the form of PageRank signals. In the SEO business, this is often referred to as “link authority” or “link juice.”

You don’t need to put this rel tag in your link because it’s the default status of a link.

Dofollow backlinks are the main goal of link-building campaigns. While Google does recognize other links, it’s generally assumed that dofollow links 


The nofollow rel tag tells Google that you do not wish to pass link authority through the outbound link for a variety of reasons.

Perhaps you don’t want to give your competitors any link juice, but it’s necessary to link to their site. Perhaps the link is paid for, like an affiliate link — the sponsored rel tag is preferred in this case, but the nofollow tag is technically acceptable.

In some cases, we even use nofollow rel tags as a way to link to a site featuring information we don’t agree with for the purposes of research and journalism.

Google may still crawl the linked web page, but with the nofollow rel tag in mind. Google also considers the nofollow rel tag more of a “hint” when looking at backlinks for ranking purposes. 

Nofollow backlinks are not as strong a ranking signal as dofollow backlinks. However, according to Google analyst John Mueller, Google’s complex algorithm does consider these tags as a factor but does not “ignore” the links altogether.


This rel tag marks a link as user-generated content. The UGC rel tag may be used for forum posts or user reviews or even Tweets. But you don’t really have to use this tag.

This rel tag was only introduced in 2019, so you may see a lot of pre-2019 links to user-generated content with only a nofollow attribute.

In most cases, forums, comment sections, and review sections of websites have built-in functions to add UGC or nofollow tags to all user-generated content.

UGC is most useful for differentiating when a website owner wants to pass link authority to another website versus when a website visitor includes a link. It even de-incentivizes spammy commenting.

The sponsored rel tag denotes when a link was paid for through legitimate means like an affiliate program, product placement, etc. Marking paid content with a nofollow rel tag is still acceptable to Google. If you don’t mark paid links with any tag, Google may penalize you.

This rel tag was only introduced in 2019, so you may see a lot of pre-2019 sponsored links with only a nofollow attribute.

Google’s algorithm values understanding which links a site owner profits from because those links  

Why is link building important? Backlinks matter for search engine optimization because Google (or whatever search engine you’re using) places a lot of value on the sites that link to your site. Link building is important because you, as a site owner/marketer, can accelerate how quickly you earn these backlinks.

The more authoritative or relevant the backlinking site, the more authority or relevance you gain. 

Google pays attention to backlinks between sites because they’re the quickest way to tell if real-life people and high-authority websites think your content is high-quality. 

What is the relationship between link building and SEO? When another site links to yours, Google assumes they are willing to pass your site referral traffic because your content is worthwhile.

If you have backlinks from high-authority sites, Google considers your content valuable and trustworthy. High-authority sites include websites that already have a great backlink profile, such as social media, newspapers, universities, famous institutions, and even Wikipedia.

Google doesn’t automatically disregard your content simply because it has no links pointing to it. But if it comes down to two equally high-quality pages, Google will frequently rank the one with more backlinks higher on the SERP (search engine results page).

By now, you may have seen “Domain Authority” measures popularized by several SEO tools like Ahrefs or SEMrush. Domain authority has everything to do with a site’s backlinks. The higher the domain authority, the better their backlink profile.

Important: I mentioned earlier that social media sites boast a high domain authority. It’s critical to understand that user-generated content (UGC) is essentially a nofollow backlink. 

For instance, if you post a link on Facebook or in the comments section of a website, Google will almost certainly ignore that link.

Is domain authority the only thing that matters?

No, domain authority is not the only thing that matters in SEO. The quality of your content, the rel tags attached to the hyperlink, the consistency of your publishing schedule, your sitewide SEO, and other ranking factors also affect SEO.

Google doesn’t officially use a “domain authority” to measure your backlink profile even though tools like Ahrefs, Moz, and SEMrush do. Google determines a site’s domain authority in terms of how to rank its content, but there is no number assigned to any website. 

Seriously, take it from the Google Man on Twitter himself:

A site with fewer backlinks from a more trustworthy source could rank above a site with a bunch of low-authority backlinks. This is especially true for YMYL (Your Money or Your Life) content with high EAT (Expertise, Authoritativeness, and Trust) standards.

Try to get good links from highly visible and trustworthy sources. Just don’t forget that it’s also helpful to obtain backlinks from less visible, but hyper-relevant sources.

High-authority backlinks that are irrelevant are not as valuable as relevant backlinks from smaller sites. One link from Business Insider might seem like a huge win, but it’s just as or even more valuable to get a few links from hyper-relevant sources.

Aim for backlinks from your field. Here are a few examples:

  • If your site talks about book publishing, seek backlinks from publishers, authors, and book reviewers.
  • If your site talks about songwriting, seek backlinks from musicians, music industry agents, and instrument makers.
  • If your site talks about packaging, seek backlinks from cardboard distributors, packing tape manufacturers, and truck rental companies.
  • If you are a brick-and-mortar business or a business with a more localized customer base, seek backlinks from other local companies, associations, and influencers.

To Follow or to Nofollow?

If you want to pass link juice from your site to others, leave the rel tag on your hyperlink blank, and it will default to dofollow.

If you do not want to pass link juice to a competitor or a site with whom you do not wish to associate or boost, mark the link nofollow.

If the link is paid for in any way, mark it sponsored or nofollow. Google prefers a sponsored rel tag, but they concede that a nofollow rel tag (which was standard practice 2005-2019) is acceptable.

Important: Don’t pay for links. It’s tempting to game the system and manipulate Google’s PageRank by buying backlinks. However, Google states it clearly in their Webmaster Guidelines:

“Any links intended to manipulate PageRank or a site’s ranking in Google search results may be considered part of a link scheme and a violation of Google’s Webmaster Guidelines.”

– Google Webmaster Guidelines

What are the benefits of link building? The main benefit of building links to your content is Google is more likely to rank your page higher on search engine results pages (SERPs).

A side effect of link building is that your content has to be absolutely killer to start with. High-quality content is more likely to procure backlinks, but it is also more likely to retain readers who click onto your page via organic search. 

Google notices when people linger or scroll or click on your page.

A side note: As an SEO pro who’s worked on many YMYL sites, I can tell you that some of the content our clients have published outranks competitors with a small fraction of the backlinks.

Links matter, but they are not the only thing that matters.

Another benefit of backlink building is relationship building. Once you establish a relationship through backlink building, you may be able to continue that relationship to procure future backlinks. Every backlink may feel a little easier to obtain over time.

There’s another bonus to this relationship-building approach: Establishing connections with other websites can lead to other opportunities on social media, email lists, and the like.

Many of the link building tactics listed below involve email outreach. Here are some email crafting tips and tricks:

  • Personalize the beginning of every email. If you can’t address the recipient by name, start with “Happy Monday, friends!” or “Glad to get in touch with you,”.
  • Personalize the body of the email. Mention a unique feature of the site you’re contacting. Compliment the aesthetics or a specific post. In general, the point of link building outreach is to clearly be a human being, not a robot. So, truly examine the site, get to know it, and do a bit of digging. Don’t be disingenuous.
  • Offer value. (Not literal money.) People are much more likely to respond to an email that offers free value upfront. If you’re a nonprofit, a tax-deductible (non-monetary) contribution counts as added value. If you’re an SEO, humbly suggest a simple on-page SEO change they can make to their site. If you have a killer blog, suggest they read a life-changing blog post. There are lots of ways to add value. You have to get creative. A literal exchange of services is against Google’s Webmaster Guidelines.
  • Keep paragraphs short. No one wants to read a block of text. Keep your paragraphs short and use bullet points where possible. In fact, keep your email as brief as possible.
  • Cordial is key. Keep your email cordial and polite. Don’t accuse recipients of anything, and don’t insult them. Thank them at the end of each email.
  • Download Grammarly or ProWritingAid. Consider downloading Grammarly to make sure your emails are on fleek. Typos may not scare off everyone, but they may scare off just the right person to mess with your ROI.
  • Avoid URLs and attachments if possible. Try not to use URLs or hyperlinks in the body of your email whenever you can except for links to the recipient’s own site. A lot of spam filters will throw your email in the spam folder simply because you’ve never sent them an email before, and the filter thinks the presence of a hyperlink looks suspicious. This is true on contact forms as well.

There’s an art to link building; it’s not just formulaic. Personally, I agree with Tim Suolo’s plea… 

Whatever you do, don’t just use a generic template.

Seriously. Please stop it.

Let’s talk about the 9 link building strategies you can employ to boost your domain authority and rank higher on Google. These are white hat content marketing strategies meant to earn you high-quality links. 

(We don’t endorse any grey or black hat SEO, even for a great link.)

How do I start building links? You start building links by creating great content. Once you have link-worthy content, then you can start building backlinks.

1. Build Superior Content

If you build it, they will come. Not always true, but sometimes it pays off.

Write superior content or build a superior tool. If a competitor has outdated information, update your website to reflect the most up-to-date info.

Unfortunately, this may take a while There’s no guarantee it will ever rank in the first place for Google or readers to realize your content is superior to everyone else’s.

That’s when you send out those cold emails, letting people know your amazing content exists.

Honestly, this may come off as aggressive, in bad faith, and just plain icky. The person you’re emailing may have built a relationship with the content creator you’re trying to snipe a backlink from. There are a lot of ways this backlink building strategy can go badly.

But there are several ways to make a “superior content” strategy (sometimes called the “skyscraper technique”) work:

  1. You can try to snipe quality backlinks from a competitor by emailing those who backlink to the competitor and making the case that your content is of superior value to their readers. Whatever you do, don’t badmouth the original writer — you’ll sound petty. Keep it business, not personal.
  2. Contact sites interested in similar topics to let them know you have amazing content, the likes of which they don’t yet link to.
  3. Advertise the web page on Google, Facebook, etc., which may attract bloggers who are always looking for valuable content to offer their readers via a backlink.
  4. Simply create your link-worthy content, and hope it gets in front of the right eyes. This way is the least likely to bear fast fruit, but it’s also the ultimate goal of amazing content.

2. Guest Blogging

This one is pretty self-explanatory. Guest blogging is a great opportunity to build relationships, get your name out there, and earn a dofollow backlink in the process.

Good manners are important when backlinking within a guest post. Limit “self-serving” backlinks to 1 within the article and 1-3 within your guest author bio, depending on how short it is.

Site owners for whom you’re guest blogging can tell when you’re packing a post with a bunch of bull.

Who knows? The site for which you guest post may run multiple sites. Or they may be friends with other site owners. Guest blogging is a great backlinking tool, as well as a great networking tool.

While this tactic does still work, many sites now publicly state that they do not accept solicitations for guest posts. Unfortunately, this kind of outreach has become such a spammy problem that it’s common to ignore the requests altogether.

3. Create a Useful Tool or Infographic

People love “linkable assets.” 

On-page tools, infographics, calculators — people will happily backlink to effective tools that their friends or their audience will get practical value out of.

What else can be said? Figure out what tools your readers could use, and make it.

  • If you’re a novel writing blog, a plotline generator might generate a lot of backlinks.
  • If you’re a tech company, create an ROI calculator that readers can use for clients.
  • If you’re a musical blog, free guitar lesson videos could up your backlink profile.
  • If you’re a real estate agent, create a unique mortgage estimator to attract both users, clients, and backlinks.

Broken link building is pretty straightforward. Here’s how it works:

  1. Look for broken links with a bunch of referring domains.
  2. Create a piece of content that can replace the 404 page.
  3. Reach out to everyone who was linking to the broken page and let them know you’ve created a replacement.

Broken backlinks are bad for SEO, so the people you email might be thankful that you pointed this out in the first place.

Similar to building superior content, this strategy depends on you building great content before you reach out to potential backlinkers.

To find broken links, I use Ahrefs or a similar tool to look for broken inbound links on competitors’ websites.

You could even check for broken outgoing links on competitors’ sites, but this might not return the relevant info you’re looking for.

WANT MORE? This article on broken link building by Ahrefs is an excellent resource.

5. Find Unlinked Mentions

You can search for places on the Internet where your site or people closely connected to your site are mentioned, but a link to your site does not appear.

This is one of the easiest link building efforts because:

  1. Whoever you are contacting already knows you exist; your site was enough to mention it somewhere on their site.
  2. As long as your email outreach is cordial, many people will concede that not linking to it in the first place was a mistake.

Plus, it’s easy to do. To find unlinked brand mentions, you can use a tool like Moz or Ahrefs, or even Google itself. 

Ahrefs’ Joshua Hardwick explains how to use their tool to do it in this video:

It’s often easier to regain lost backlinks than to build new links from scratch. Many SEO tools allow you to identify the backlinks you recently lost. If you can identify why you lost a backlink, you may be able to regain it.

This is known as link reclamation.

For example, if you had a lot of backlinks while you were offering a deal on your product, you might consider running another deal to earn backlinks from coupon websites and deal-hungry blogs.

7. Get Press Mentions

Content marketing, which includes SEO, is all about offering free value. One way to offer value in exchange for a link is to offer expert quotes to journalists in exchange for a link and a mention back to your site.

The gold standard for press mentions is HARO, or “Help a Reporter Out.” You can sign up for free as a “Source” on HARO to get daily alerts from journalists writing about a huge variety of different topics.

Pro tip: Our agency uses an app called Link Sourcery that simplifies the HARO process and makes it more straightforward to sort through and respond to queries.

We’ve been busy the last several months, but even responding to just a few HAROs, we’ve landed 13 press mentions in the first 8 months of 2021. You have to offer truly expert, high-quality quotes, but it works.

8. Advertise Your Page

Paying to advertise your page on Google (or many other sites, really) can attract more eyeballs to your page. If the right people find your page, they could link to it and share it with their friends, network, or audience.

If you’re involved with relevant Facebook groups or subreddits that allow self-promotion, you might “advertise” your page with users in these groups. If anyone runs a blog, and if your content is useful and high-quality, you may just earn yourself a backlink.

Nofollow links are a normal part of a healthy backlink profile. Backlinks with a UGC (user-generated content) rel tag are a type of nofollow link, but anyone can post that link on their social media or in a comment on a blog.

Although UGC and nofollow links should not be your main focus, only procuring high-authority dofollow backlinks might make Google think you’re obtaining these backlinks unnaturally, which is a big no-no. UGC links are not dirty. They’re a part of any healthy backlink profile.

A site’s own internal linking structure is important for Google to understand the relationship of all the pages on the site. Internal link building is one of the most frequently overlooked ways to strengthen your site’s relevance and authority.

You should structure and regularly update your internal backlinks.

Make sure your cornerstone piece within a category (also called a content hub or silo) contains links to every article within that category. Each article within a category should have a link to the cornerstone (pillar) piece, near the top of each article.

Want more? Check out Yoast’s great post on how to nail an internal link building strategy.

Most importantly, there should be very few to no “orphan pages” indexed on your site. An orphan page is when there is no internal link to a given page. This means there’s no way for a user to reach this page while normally navigating your site.

When Google indexes an orphan page, it may warn you to add a link pointing to that orphan page. Orphan pages can be serious SEO problems that need to be fixed.

Note: It’s okay to have orphan pages that serve an internal or customer-focused purpose but that you don’t want to be found in search. In these cases, it’s best to de-index the page so Google Search Console doesn’t identify it as a potential error.

You need good backlink building tools to run effective backlink building strategies.

General SEO Tools

To identify broken backlinks, lost backlinks, and other link opportunities, SEO tools like Ahrefs, SEMrush, Moz, and Ubersuggest can turn impossible tasks into a breeze.

Each SEO tool has its benefits, but we recommend Ahrefs for its time-tested, expansive database of sheer info and capability. Ahrefs costs anywhere from $99 to $999, so it might not fit beginner SEOs’ budgets.

Linkody and Majestic are two budget-friendlier options for backlink tracking.

Finding relevant blog sites is essential to many backlink building campaigns. High-authority and hyper-relevant blogs can really boost your backlink profile.

Link Prospector is fantastic for figuring where to start in a backlink building campaign. This tool can arrange link building prospects by relevance (they call it Link Target Score).

GroupHigh boasts the largest blog search engine in the world. You can use GroupHigh to only search for the most relevant blog sites, to whom you can then reach out and ask for a backlink.

NinjaOutreach is similar to GroupHigh, but is more of a database of influencers, instead of specifically blogs.

HARO (Help A Reporter Out) allows you to only receive inquiries from relevant categories, such as Biotech & Healthcare, Travel, or Entertainment & Media. When you respond to a HARO query, and the reporter accepts your response, they will usually give you a backlink when they publish.


For many backlink building strategies, you will need an email address for the domain you’re requesting a link to. This seems simple, but some people get this part wrong.

First of all, it helps if you use an email address that has been in use for some time. Brand new email addresses are more likely to seem spammy, to both spam filters and humans.

Secondly, you don’t have to get fancy. Gmail offers a great email service — improved even more by apps like Mixmax. If you use outdated email services, you may not be able to use all the functionalities that come with Gmail.

Please, no Linux email servers that don’t allow you to format text.

Mailshake and Buzzstream are two email outreach tools that can improve your output and efficiency throughout a large-scale backlink building campaign.


Sometimes, you need to disavow a backlink — whether you don’t want to be associated with the content or you think it’s hurting your backlink profile. makes it easy to create a file containing properly formatted info on all the links you want to disavow. Then you give that disavow file to Google.

Cognitiveseo allows you to detect unnatural links that you might otherwise miss. Unnatural links might cost you in the future, so it’s wise to disavow them sooner rather than later.

If you’re working with an agency, make sure you’re not partaking in black hat link building strategies. “Black hat” means Google will likely penalize you for trying to game the system.

What is the difference between a natural link and a paid link? The main difference between a natural link and a paid link is that you earned a natural link without money, products, or services. You pay for a paid link, whether that is with dollars, “free” products, or promises.

You don’t want to use black hat link building techniques because they may negatively affect your search ranking. These black hat SEO practices won’t work in the long term because they aren’t good for user experience.

8 black hat link building strategies you should avoid at all costs:

  1. Paid link building. Don’t pay for backlinks, not even with a free product. Backlinks need to be earned naturally. If Google discovers you’re buying links (without marking it “sponsored” or “nofollow”), they could penalize you and forbid your site from appearing on search results.
  2. Link trading. Don’t trade a backlink for a backlink excessively. Link trading can be natural when you’re building backlinks — it’s normal to find sites that mutually offer content marketing value to one another. However, if Google notices you and another site continuously trade backlinks back and forth, they may penalize you because it could eventually look unnatural.
  3. Blog and forum spam. Don’t spam comment sections or forums with links to your site. Although this will likely be marked as UGC (user-generated content), Google still frowns upon this practice.
  4. Large-scale guest posting. Don’t constantly guest post with the intent of backlink building. Guest posting on occasion is a great backlink building opportunity, but overusing this strategy may incur the wrath of Google’s algorithm.
  5. Private blogging networks. Don’t run a hundred sites that all constantly backlink to each other. This seems oddly specific, but Google found a bunch of private blogging networks (PBNs) a few years ago that were gaming the system, and thereafter added PBNs to their list of black hat practices.
  6. Sitewide backlinks. Don’t ask for a backlink on every page of a site, for instance, on the footer or a sitewide sidebar.
  7. Exact match. Don’t make backlinks where the anchor text is hyper-optimized for what the link goes to. This goes for backlinks to and from your site. For example, if every backlink for your article contains the exact anchor text “CBD oil”, Google may get suspicious.
  8. Sneaky redirects. Don’t purchase defunct URLs with robust backlink profiles, then redirect that URL to one of your unrelated pages. For instance, if the URL “” went dark, then you bought that domain name and redirected it to your site about classic cars, that’s a sneaky redirect. Irrelevant redirects may earn you a Google penalty.

Got a brainwave for other backlink building strategies I should include in future updates? @ the Clara founder, Rebekah, on Twitter with your ideas.