What are Backlinks?

Backlinks (also called inbound links or incoming links) are links from other websites that point to your website. They function as "votes of confidence"—each quality backlink signals to search engines that your content is valuable and trustworthy, making backlinks one of Google's top three ranking factors alongside content quality and user experience.

Why do backlinks matter?

Backlinks are one of Google's top 3 ranking factors and play a crucial role in SEO success:

Authority Transfer

Links from high-authority sites pass "link juice" to your site, directly improving your domain authority and helping pages rank higher in search results. When an authoritative site links to you, search engines interpret this as an endorsement of your content quality.

Credibility Signal

Many quality backlinks from diverse, relevant sources indicate your content is trustworthy and valuable. This social proof helps search engines determine which sites deserve to rank highly for competitive keywords.

Discovery

Search engines find new pages by following links across the web. Without backlinks, search engine crawlers might never discover your content, leaving it invisible in search results no matter how well-optimized it is.

Referral Traffic

Users click links to reach your site directly, often bringing highly qualified visitors who are already interested in your topic area. This referral traffic tends to have better engagement metrics than other sources.

What are the different types of backlinks?

Not all backlinks are created equal. Understanding quality differences helps you build an effective link profile:

High-Quality Backlinks

Authoritative sources: Links from well-established, high-domain-authority websites in your industry carry significantly more weight than links from unknown sites.

Editorial placement: Natural links embedded within the main content of a page (not sidebars or footers) signal genuine endorsement rather than manipulation.

Contextual relevance: Links from pages topically related to your content are more valuable than those from unrelated niches. A backlink from a marketing blog to your SEO tool is more powerful than one from a cooking site.

Diverse domains: 100 links from unique domains is far more valuable than 1,000 links from the same domain. Domain diversity signals authentic popularity.

Dofollow attributes: Links without the rel="nofollow" attribute pass SEO value directly to your site.

Low-Quality Backlinks

Spam domains: Links from low-authority sites, link farms, or obviously spammy sources can harm your rankings rather than help them.

Paid links without disclosure: Google penalizes sites that buy links or participate in link schemes without proper disclosure (rel="sponsored" or rel="nofollow").

Irrelevant sources: Links from completely off-topic sites suggest manipulation rather than genuine endorsement.

Sitewide links: Footer or sidebar links that appear on every page of a site look unnatural and carry less weight per instance.

Suspicious patterns: Sudden spikes in backlinks, only exact-match anchor text, or links from the same C-block IP addresses can trigger algorithm penalties.

What link attributes should I know?

HTML link attributes tell search engines how to treat the link:

Dofollow Links (default)

These are standard links without special attributes:

• Pass SEO value ("link juice") from source to destination
• Count as ranking signals in Google's algorithm
• Most valuable for building domain authority
• What you want when earning quality backlinks

Example: <a href="https://example.com">anchor text</a>

Nofollow Links

Include rel="nofollow" attribute:

• Officially don't pass direct SEO value
• Still provide traffic and brand visibility
• May pass trust signals despite Google's claims
• Required for paid or user-generated content

Example: <a href="https://example.com" rel="nofollow">anchor text</a>

Other Attributes

Sponsored: rel="sponsored" for paid links and advertisements UGC: rel="ugc" for user-generated content like comments and forum posts Multiple: Can combine attributes like rel="nofollow sponsored"

How are backlinks measured?

SEO tools use various metrics to evaluate backlink profiles:

Domain Authority (DA)

Moz's 0-100 score predicting how well a domain will rank. Higher DA sources pass more authority through their links.

Page Authority (PA)

Similar to DA but for individual pages. The linking page's authority matters more than the overall domain in many cases.

Referring Domains

The number of unique websites linking to you. This is often more important than total backlink count—1,000 links from one site is less valuable than 10 links from 10 different sites.

Total Backlinks

The count of all incoming links. Less important than quality and diversity, but still a useful metric.

Anchor Text Distribution

The clickable text in links pointing to your site. Natural profiles have varied anchor text including branded terms, URLs, generic phrases ("click here"), and occasional keyword-rich anchors.

Link Velocity

The rate at which you acquire new backlinks over time. Sudden spikes can look suspicious; steady, gradual growth appears more natural.

Toxic Score

Metrics estimating how many low-quality or spammy backlinks you have that might harm your rankings.

How do you build quality backlinks?

White-hat link building focuses on earning links through valuable content and relationships:

Content Formats That Attract Links

• Original research and data: Unique statistics people want to cite
• Ultimate guides: Comprehensive resources (3,000+ words) on specific topics
• Infographics: Visual data representations easy to embed
• Free tools: Calculators, generators, templates
• Opinion pieces: Controversial or thought-provoking takes that spark discussion
• Case studies: Real-world examples with specific results
• Expert roundups: Collecting insights from multiple authorities

What tactics should you avoid?

Black-hat and manipulative link building can trigger severe penalties:

These tactics might show short-term gains but risk:

• Manual penalties from Google's spam team
• Algorithmic devaluation of your entire domain
• Complete removal from search results
• Long recovery times (months to years)

Do backlinks help with GEO?

Backlinks aren't just for traditional SEO—they're increasingly important for AI visibility:

Source Authority for LLMs

Large Language Models prioritize information from well-linked, authoritative sites when generating responses. Strong backlink profiles signal trustworthiness to AI systems just as they do to search engines.

Citation Patterns

Content that earns many backlinks demonstrates it's citation-worthy. AI systems looking for reliable sources to reference are more likely to cite pages that other humans have deemed link-worthy.

RAG System Retrieval

RAG-powered AI retrieves content from web searches before generating answers. Pages ranking highly for relevant queries (often due to strong backlink profiles) are retrieved and cited more frequently.

Entity Recognition

Backlinks from authoritative sources help establish your brand as a recognized entity in AI knowledge graphs. This makes it easier for LLMs to understand your brand and mention it accurately in context.

Domain Trust Signals

AI systems evaluate source credibility when deciding what to cite. Domains with strong, natural backlink profiles appear more trustworthy and citation-worthy than those without external validation.

How do you check backlinks?

Use specialized tools to analyze your backlink profile and identify opportunities:

Popular Backlink Analysis Tools

Ahrefs:

• Industry-leading backlink database with ~17 trillion links
• Domain Rating (DR) metric similar to DA
• Comprehensive competitor analysis
• Content explorer to find link-worthy topics
• Pricing: Starting at $99/month

SEMrush:

• Backlink Analytics with toxic link detection
• Link building tool for outreach campaigns
• Historical backlink data tracking
• Integration with other SEO features
• Pricing: Starting at $119.95/month

Moz Link Explorer:

• Original Domain Authority metric
• Spam Score for identifying toxic links
• Link Intersect tool for competitor gap analysis
• Free limited version available
• Pricing: Starting at $99/month

Google Search Console:

• Free tool directly from Google
• Shows links Google has discovered
• Limited to your own site
• Less comprehensive than paid tools but official source

What to Look For

When auditing backlinks, analyze:

• Total referring domains vs. total backlinks
• Authority distribution (mix of high/medium/low DA sites)
• Anchor text patterns (should be varied and natural)
• Link velocity trends (steady growth vs. suspicious spikes)
• Toxic links that need disavowing
• Competitor gaps (sites linking to them but not you)
• Best-performing content (what earns the most links)

Related Concepts

• Schema Markup: Structured data that helps backlinks pass more context
• Citations: The GEO equivalent for AI-generated content
• SERP: Strong backlink profiles improve rankings in search results
• Zero-Click Search: Quality backlinks help you win featured snippets