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What Are Backlinks? Why They Matter for SEO

Backlinks are one of Google's most powerful ranking signals — and understanding them is essential for any SEO strategy. In this guide, you'll learn exactly what backlinks are, how they pass authority, what makes them high-quality, and how to build them ethically and effectively.

Rank Crown Team
March 2026
15 min read

What Are Backlinks?

A backlink (also called an inbound link, incoming link, or external link) is a hyperlink from one website that points to a page on a different website. When Website A includes a clickable link leading to a page on Website B, Website B receives a backlink from Website A.

From a technical standpoint, a backlink is just an HTML anchor tag: <a href="https://yoursite.com/page">anchor text here</a>. When a user clicks the anchor text, they are taken to your page. When a search engine crawler follows that link, it signals to Google that someone else found your page valuable enough to link to.

Backlinks are distinct from internal links (which connect pages within the same site) and from outbound links (links you place on your site pointing to other sites). The term "backlink" always refers to links coming in from an external domain.

Key Takeaway

A backlink is a vote of confidence from one site to another. Search engines use backlinks as a key signal of a page's credibility, authority, and relevance — which directly influences how high that page ranks in search results.

Why Backlinks Matter for Rankings

To understand why backlinks matter, you need to understand PageRank — the algorithm Google co-founders Larry Page and Sergey Brin developed at Stanford in the 1990s that became the foundation of Google Search.

The core insight of PageRank was simple but powerful: a web page is important if other important pages link to it. Instead of just analyzing a page's content, Google counted links as votes. A link from a highly-linked page passed more authority than a link from an obscure page. This created a recursive, self-reinforcing measure of web authority.

While Google's algorithm has evolved enormously since 1998 — now incorporating hundreds of signals including content quality, user experience, and entity recognition — backlinks remain one of the most heavily weighted ranking factors. Multiple industry studies consistently show a strong correlation between the number of high-quality referring domains and Google ranking positions.

What Backlinks Tell Google

Authority: Links from well-established, authoritative sites in your industry signal to Google that your content is credible and trustworthy.
Relevance: When a site in a related field links to you, it confirms your page's topical relevance to that subject area.
Discovery: Googlebot follows links to discover new pages. A well-linked page gets crawled more frequently, meaning updates are indexed faster.
Popularity: Many backlinks from diverse, independent sources signal that people genuinely find your content valuable — not just the content author.

It's worth noting that not all backlinks are equal. A single link from a major industry publication (high authority, highly relevant) can have more impact on your rankings than hundreds of links from irrelevant, low-quality directories. Understanding what makes a backlink valuable is just as important as knowing you need them.

Types of Backlinks

Not all backlinks are created equal — and understanding the differences helps you prioritize which links to pursue and which to ignore (or disavow).

Dofollow vs. Nofollow

Dofollow Links

The default link type. Dofollow links pass PageRank (link equity or "link juice") from the linking page to the linked page. They directly contribute to the linked page's authority and ranking power. Most editorial links — when a site links to yours because they genuinely want to — are dofollow.

Nofollow Links

Links with the rel="nofollow" attribute. Google treats them as a hint (not a hard rule) not to pass PageRank. Common on comment sections, forums, and user-generated content. While they don't pass direct authority, they can still drive referral traffic and contribute to a natural link profile.

Variants: rel="sponsored" (paid links), rel="ugc" (user-generated content)

By Acquisition Method

Editorial Links

Highest value

Earned organically when a writer or editor chooses to link to your content because it genuinely helps their readers. These are the gold standard — they signal real endorsement and carry the most ranking power.

Guest Post Links

High value

You write an article for another site's blog and receive a link back to your site in the author bio or within the content. Effective when the host site is genuinely relevant and authoritative. Avoid low-quality 'article farm' guest posting — Google can detect and discounts these.

Resource Page Links

High value

Many sites maintain 'resources' or 'links' pages listing helpful tools and content for their audience. Getting listed on a relevant, curated resource page is a natural and respected way to earn links.

Directory Links

Low to medium value

Listings in industry-specific directories can provide genuine value, especially locally. However, generic web directories with no editorial standards are largely ignored by Google and not worth pursuing.

Paid / Sponsored Links

Must be disclosed

Links you pay for must carry the rel='sponsored' attribute under Google's guidelines. Undisclosed paid links are a violation of Google's webmaster guidelines and can result in a manual penalty. Always be transparent about paid placements.

What Makes a High-Quality Backlink?

Understanding what makes a backlink valuable helps you evaluate link building opportunities and prioritize your outreach efforts. Here are the key quality signals:

Authority of the Linking Domain

A link from a site with a high Domain Rating (DR 70+) carries significantly more weight than a link from a new blog with DR 5. Sites that are themselves well-linked earn more authority to pass on. Before pursuing a link, check the linking domain's DR in Rank Crown's Site Explorer.

Topical Relevance

Google's algorithms heavily weight topical context. A link from a highly relevant industry site (e.g., a digital marketing blog linking to your SEO tool) carries more SEO value than a link from an unrelated site (e.g., a cooking blog linking to your SEO tool), even if both have similar DR scores.

Anchor Text

The clickable text of the link signals to Google what the linked page is about. Descriptive, keyword-rich anchor text ('best keyword research tool') is more informative than generic text ('click here'). However, over-optimized exact-match anchor text at scale is a manipulation signal — a natural backlink profile has varied anchor text.

Link Placement on the Page

Links embedded naturally within the main body content of an article carry more weight than links buried in footers, sidebars, or author bio sections. Contextual links — where surrounding content is relevant to your linked page — are the most valuable placement.

Traffic of the Linking Page

Links from pages that receive real organic traffic from Google are a stronger quality signal. A link from a page ranking on page one for competitive queries likely carries more authority than a link from an orphan page nobody reads — even on an otherwise strong domain.

Editorial Standards of the Linking Site

Sites with genuine editorial review, real authors, and quality standards give more trustworthy links. If a site links to anyone who pays or submits content without review, Google likely discounts those links heavily.

How to Check Your Backlink Profile

Regularly auditing your backlink profile is essential for two reasons: to understand your current link authority, and to catch toxic or spammy links before they harm your rankings. Here's how to do a comprehensive backlink analysis using Rank Crown:

01

Get a full backlink overview

Open Rank Crown's Site Explorer and enter your domain. The overview shows your Domain Rating (DR), total referring domains, total backlinks, and your organic traffic estimate. The referring domains count is the most important — it's the number of unique websites linking to you.

02

Analyze referring domains by quality

In the Referring Domains report, sort by DR to see your highest-authority links first. Are there well-known publications, industry sites, and relevant blogs in your top 20? If your best links are DR 5–15 directories, there's significant room to improve your link profile.

03

Review your anchor text distribution

Check the Anchors report. A natural backlink profile has diverse anchor text — a mix of branded (your company name), naked URLs (https://yoursite.com), generic ('click here', 'read more'), and some descriptive keywords. If 70%+ of your anchors are exact-match keywords, that's an over-optimization signal.

04

Check for broken backlinks

Filter for backlinks pointing to pages that return 404 errors. These are lost links — someone is linking to your site, but that page no longer exists. Redirect those URLs to relevant live pages and recapture that link equity.

05

Monitor new and lost backlinks

Track links gained and lost over time. Sudden drops in referring domains can signal that authoritative sites removed links to you — worth investigating. Sudden spikes in low-quality links can indicate a negative SEO attack.

Backlink Metrics Explained

Several third-party metrics help you evaluate link authority quickly. These are not Google's actual PageRank (which is not publicly disclosed), but they are useful proxies. Here are the key ones you'll encounter:

Domain Rating (DR)

Rank Crown / Ahrefs

A 0–100 score representing the strength of a website's entire backlink profile. Higher DR means more authority to pass through links. DR 50+ is generally considered strong for most niches. Use this to evaluate the authority of potential link partners.

Domain Authority (DA)

Moz

Moz's equivalent of DR — a 0–100 score predicting ranking ability based on link profile strength. Historically the most widely cited metric, though DR has become increasingly common. Both are useful comparisons, but neither is a Google ranking factor.

Referring Domains

Universal

The count of unique websites that have at least one link pointing to your site. This is more meaningful than total backlinks — 500 links from 500 different sites is far more valuable than 500 links from the same site. Tracking referring domain growth over time is the best measure of your link building progress.

URL Rating (UR)

Rank Crown / Ahrefs

The link authority score of a specific page (not the whole domain), on a 0–100 scale. UR is more directly relevant to how well an individual page will rank. High UR means that page has many high-quality inbound links.

Spam Score

Moz

A metric estimating the likelihood that a site has spammy characteristics, based on patterns correlating with penalized sites. High spam score links (30%+) are candidates for disavowal. Use this in combination with a manual review of the site — automated scores can produce false positives.

Link Velocity

Tracked over time

The rate at which a site gains or loses backlinks over time. Sudden, unnatural spikes in link acquisition can trigger algorithmic scrutiny. Steady, consistent link growth looks natural and is preferred. Monitor this trend in Rank Crown's referring domains over time chart.

Analyze Your Backlink Profile

Rank Crown's Backlink Analysis shows you every link pointing to your site — who's linking, with what anchor text, from what DR, and whether links are dofollow or nofollow. Analyze your profile, identify gaps, and find the same link sources your competitors use.