What Are Backlinks In SEO and Why Are They Important?

Updated by Chima Mmeje — April 3, 2025.

Backlinks, or inbound links, are hyperlinks from one website to another. They signal trust, showing that one site values another’s content. Search engines like Google use backlinks as ranking factors, treating them as “votes of confidence” that indicate a page’s authority and relevance in search engine optimization.

Earning backlinks from reputable sources tells search engines that content is valuable, helping it rank higher. Backlinks also contribute to a site’s E-E-A-T** (Experience, Expertise, Authoritativeness, and Trustworthiness), a key factor in how Google evaluates content.

For example, a British hedgehog website links to a hedgehog sighting map as a helpful resource. The map receives a backlink from the hedgehog site, typically appearing as underlined, clickable text within the content.

Backlinks are often blue and underlined, but site owners can style them differently. Hovering over a link changes the cursor to a pointer and shows the destination URL in the browser’s bottom-left corner.

Backlinks are essential for SEO, signaling trust and authority to search engines. Below are several reasons to prioritize backlinks for SEO.

Help search engines determine relevance and authority

Search engines use backlinks to evaluate a page’s credibility. Google’s algorithm considers links as trust signals, using concepts like PageRank and link equity to distribute ranking value across the web. 

When authoritative sites link to a page, it signals to Google that the content is valuable and worth referencing, thereby improving its position on search engine results pages. 

For example, we can see that HubSpot is the leading authority for Inbound Marketing through metrics like the quality of links pointing to the page which influences their Page Authority.

Improve your rankings

Google ranks pages based on hundreds of factors, and backlinks remain one of the strongest signals. Pages with more high-quality backlinks tend to rank higher because search engines interpret them as endorsements. However, not all backlinks are equal—links from trusted, relevant sources carry more weight than random or low-quality links.

For example, if you turn on your MozBar and check the keyword “pram for triplets”, you’ll notice that the top pages ranking for this keyword have a ton of backlinks, which influences their ability to rank for such a competitive keyword.

Earn referral traffic

Backlinks drive direct traffic. When a high-authority site links to your content, its audience can click through and visit your site, generating relevant traffic that could lead to conversions. Unlike paid ads, referral traffic from backlinks is sustained over time, providing long-term value.

For example, when I search for "research on walking", Harvard Health is one of the top sites ranking for the keyword.

Further analysis via Moz Link Explorer reveals that the page is earning referral traffic from popular sites like Healthline, CNET, and the New York Times.

Build Domain Authority

Backlinks from various referring domains play a key role in determining a website’s Domain Authority, a metric that estimates how well a site is likely to rank in search results. High-DA websites tend to have a strong backlink profile, with links from reputable sources signaling trust and credibility.

Moz's Meghan Pahinui explains how to improve your Domain Authority in this video below.

Improve search engine crawling and indexing

Search engines like Google use automated crawlers to discover and index content by following links from one page to another. A page must be found before it can appear in search results, and the simplest way that happens is through backlinks. 

Also, Google has also stated that links from prominent websites are one of the factors they use to determine content quality.

Links create pathways across the web, allowing search engines to continuously discover new content.

Improve competitive intelligence

Because backlinks influence rankings, analyzing competitors’ link profiles can reveal valuable opportunities. Sites that link to industry competitors are more likely to be relevant sources for your own content. 

The goal is to earn links from high-quality, topically relevant links rather than unrelated or low-value sources that represent link spam.

For example, if you wanted to rank for the keyword "how to code," you would analyze the SERPs to see who's ranking for that keyword. From the search results, you can see that Code Academy is ranking for the keywords. To analyze who's linking to them, install the free MozBar, reload the page, and click Links. 

It will take you to Moz Link Explorer and show link metrics for that specific page. 

For example, Code Academy is attracting backlinks from authoritative websites like CNBC and GitHub, passing authority to their page.

If you were competing for a similar keyword, you'd need to create a strategy to attract backlinks from similar websites with high authority.

Understanding the various types of backlinks is crucial for building a strong link profile. Here are some of the key types:

Dofollow backlinks

Dofollow backlinks pass link equity from one site to another, helping improve search rankings. These links signal to search engines that the linked content is valuable and relevant. Most standard links are dofollow unless specified otherwise.

Nofollow backlinks

Nofollow backlinks include a tag that tells search engines not to pass ranking value. While they don’t directly impact rankings, they can still drive referral traffic, increase brand visibility, and lead to other valuable link-building opportunities.

You can view dofollow and nofollow backlinks in Moz Link Explorer.  Navigate to Inbound Links and enter the page URL

When the results populate, scroll down to Link Types and select follow or nofollow from the drop-down menu.

If a link is nofollowed, you could contact the author or webmaster and ask them to make it a dofollow link.

Editorial backlinks

Editorial backlinks are naturally earned when other websites link to your content because they find it valuable. These are some of the most effective links for SEO since they come from authoritative sources without direct influence from the site being linked to.

For example, in a blog post about the importance of brand for SEO, we linked to research from Page One Power and another from Sparktoro to support the argument with data.

Guest post backlinks

Guest blogging allows you to contribute content to another site in exchange for a backlink. When done correctly, these links help establish credibility while driving traffic. However, excessive guest posting on low-quality sites can appear manipulative and may not provide SEO benefits.

For example, Nick LeRoy wrote a guest post for the Moz blog and linked to relevant resources like his website and newsletter, earning a dofollow link from an authoritative website in his niche.

Directory and resource page links

Submitting your site to reputable directories and industry-specific resource pages can generate backlinks. These links typically don’t carry as much ranking value as editorial links, but they can still be useful for local SEO and brand visibility.

For example, you can see that Prime Solicitors is listed in multiple directories, including The Law Society.

User-generated content (UGC) and sponsored links

Links in user-generated content, such as forum posts and blog comments, are often tagged with the UGC attribute to indicate they weren’t placed by the website owner. Similarly, sponsored links include a tag that signals a paid or promotional relationship. These tags prevent search engines from passing ranking value to ensure compliance with link policies.

For example, in a forum for park runners, a user asked for recommendations on where to buy running shoes, and someone responded with links to two websites. The websites earn referral traffic that could generate revenue. They also earn brand mention and authority signals from users who see them as trustworthy.

Social media links

While links from social media platforms are typically nofollow, they can still drive traffic and increase visibility. Engaging in industry discussions and sharing valuable content can encourage organic link building and brand recognition.

Relevance

Links from websites related to your industry or topic carry more weight. Search engines assess whether the linking site’s content aligns with yours, as relevant links provide stronger ranking signals. 

For example, a veterinary clinic receiving a backlink from a well-known pet care blog provides strong relevance, whereas a backlink from a car dealership’s website would be less meaningful.

Authority

The authority of the linking website affects the value of a backlink. Links from trusted, high-authority domains pass more ranking value than those from low-quality or spammy sites. Search engines measure authority using factors like domain history, content quality, and existing backlinks.

 For instance, a link to a nutrition research paper from the World Health Organization (WHO) signals strong authority, while a link from a newly launched personal blog with no reputation carries little weight.

Placement

Where a link appears on a page matters. Backlinks placed within the main body of content carry more weight than those in footers, sidebars, or comment sections. Contextual links are more likely to be clicked and trusted by users, reinforcing their SEO value.

For example, a link to a handmade jewelry shop included in the body of a fashion influencer’s blog post is more powerful than one placed at the bottom of the page in a list of miscellaneous links. 

Anchor text optimization

Anchor text, the clickable words in a link should be descriptive and relevant to the linked page’s content. Optimized anchor text provides context for search engines and users, improving the link’s impact.  

 However, over-optimized, keyword-stuffed anchor text can appear manipulative and may trigger penalties. A mix of branded, generic, and keyword-rich anchor text creates a natural link profile.

For example, a well-optimized link for a home improvement website might be: "Explore these expert-recommended kitchen remodeling ideas." The phrase "kitchen remodeling ideas" tells both users and search engines what to expect from the link.

Editorial value

The best backlinks are naturally earned because other sites find the content valuable. These editorial backlinks hold more weight than links placed through exchanges, sponsorships, or automated link-building tactics. 

Google prioritizes organic, high-quality links as indicators of content trustworthiness. For example, a fashion retailer's appearance in a Vogue article about upcoming trends is more valuable than a link placed in a directory of clothing stores.

Here are some effective link building strategies to help you build a robust backlink profile:

Content marketing

Creating valuable content encourages natural backlinks. High-quality, informative resources are more likely to be cited by other websites, helping to build backlinks effectively.

Strategies for earning backlinks through content marketing include:

• Opinion pieces and thought leadership
• Guides and how-to articles 
• Original research and surveys 
• Infographics and visual content
• Case studies and success stories

Broken link building

Find and replace broken links on other websites with your own relevant content.

Steps for earning backlinks through broken link building include:

• Identify broken links with Moz Link Explorer
• Create or repurpose content as a replacement
• Reach out to site owners to suggest your content as an updated resource
• Make your request valuable and frame it as a helpful fix rather than a favor

Get listed on directories and resource pages

Submitting to high-quality directories and industry resource pages can generate backlinks.

Ways to earn backlinks from directories and resource pages include:

• Industry directories:
• Supplier and partner websites
• Awards and certifications
• Professional associations

Networking and partnerships

Collaborations with businesses, bloggers, and organizations create backlink opportunities.

Strategies for earning backlinks through networking include:

•  Partner with other companies in your industry who are not direct competitors to create content like webinars or research reports.
• Get listed on event sites as a speaker.
• Support local events or charities for mentions.

Digital PR

Earning media coverage and mentions from authoritative sources increases backlinks and visibility. 

Tactics for earning backlinks through digital PR include:

• Pitch unique stories that interest journalists
• Provide expert insights on emerging topics
• Distribute press releases to reach a wider audience
• Publish research that reporters will cite

You can view your backlinks using SEO tools like Moz’s Link Explorer to analyze your link profile and those of your competitors.

Log into your Moz Pro account and click Inbound Links under Link Research.

The next page shows your total number of linking domains, inbound links, and how many are dofollow.

Scroll down to see who’s linking to you, the anchor text they use, and their Domain and Page Authority.

This process also works if you want to see backlinks pointing toward a specific page on your website.

Get the backlink data

The first step in auditing your backlink profile is gathering data from Moz’s Link Explorer. Next, enter your domain and you can see who is linking to you, the quality of those links, and any recent changes. 

Identify and disavow toxic backlinks

Low-quality or spammy backlinks can harm your rankings. Use Link Explorer to find links from suspicious sites, such as link farms, irrelevant directories, or spam-heavy domains. Filter by Spam Score to view spammy sites linking to you.

Once you identify harmful links, you can:

• Attempt removal: Contact site owners and request link removal.
• Use Google’s Disavow Tool: If removal isn’t possible, create a disavow file and submit it through Google Search Console to prevent search engines from considering those links.

Fixing broken backlinks

Lost or broken backlinks mean missed SEO value.

Filter results by lost links in Link Explorer to view backlinks that no longer work due to:

• Deleted pages: If a linked page was removed, consider redirecting it to a relevant alternative.
• Changed URLs: If a page was moved, ensure proper 301 redirects are in place.
• Linking errors: If a site links to a mistyped URL, reach out to the site owner to correct it.

Track new backlinks

Monitoring new backlinks helps you understand which content is attracting links and where to focus future efforts. 

With the Link Explorer tool, you can:

• See the backlinks to any page
• Research competitors’ backlink profiles
• Find lost links
• Discover your link building opportunities
• Identify spammy links to your site
• Analyze the anchor text of your backlinks
• Analyze Page Authority and Domain Authority of linking domains
• Find relevant resource pages that may be interested in linking to your content

Building high-quality backlinks requires a strategic, ethical approach. Focus on earning links through valuable content and leveraging relationships. Avoid shortcuts that can harm your site’s credibility. To strengthen your backlink profile, start by analyzing your existing links with Moz’s Link Explorer and optimizing your link-building strategy for long-term SEO success.

Is it illegal to buy backlinks?

Buying backlinks violates Google’s guidelines and can result in penalties, including ranking drops or manual actions. Focus on earning links naturally.

How do you get backlinks?

You can earn backlinks by publishing link-worthy content, contributing guest posts, getting listed in directories, engaging in PR, and forming partnerships.

How many backlinks do I need to rank?

There is no set number. The quality, relevance, and authority of backlinks matter more than quantity. A few high-quality links outweigh many low-quality ones.

What’s the difference between nofollow and dofollow links?

Dofollow links pass ranking value to the linked page, while nofollow links include a tag that tells search engines not to pass ranking authority.

How do I remove bad backlinks?

Use Moz’s Link Explorer to find toxic links, request removal from site owners, or disavow harmful links in Google Search Console.

• The Beginner's Guide to Link Building - Everything you need to get started on one of the most important things you can do for your SEO.
• How to Easily Find Backlink Opportunities With Moz — Next Level
• Backlink Basics - Moz Academy
• What is off-site SEO?
• All Links are Not Created Equal: 10 Illustrations on Search Engines' Valuation of Links
• Top Tips for Non-Spammy Link Building