Understanding the different types of links—internal, external, and inbound—is fundamental to SEO success. Each serves different purposes and requires different strategies.
Definitions
Internal Links
Definition: Links that point from one page on your website to another page on the same website.
Example: Your homepage linking to your services page, or a blog post linking to another blog post on your site.
<!-- On example.com -->
<a href="/services">Our Services</a>
<!-- Points to example.com/services -->
External Links (Outbound Links)
Definition: Links from your website pointing to a different website (a different domain).
Example: Your blog post linking to a Wikipedia article or citing an industry study.
<!-- On example.com -->
<a href="https://wikipedia.org/topic">Source</a>
<!-- Points to wikipedia.org -->
Backlinks (Inbound Links)
Definition: Links from other websites pointing to your website.
Example: A news article mentioning your company and linking to your website.
<!-- On news-site.com -->
<a href="https://example.com">Example Company</a>
<!-- You receive this as a backlink -->
Visual Diagram
Your Website (example.com)
┌─────────────────────────────────────┐
│ │
│ Page A ─────────► Page B │
│ │ (Internal Link) │
│ │ │
│ ▼ │
│ Page C │
│ │
└─────────────────────────────────────┘
│ ▲
│ (External Link) │ (Backlink)
▼ │
┌─────────────────┐ ┌─────────────────┐
│ Other Site │ │ News Site │
│ (wikipedia) │ │ (news.com) │
└─────────────────┘ └─────────────────┘
The same link is described differently depending on perspective:
- From your perspective: A link from news.com = backlink (inbound)
- From news.com's perspective: Their link to you = external link (outbound)
How Each Type Affects SEO
Internal Links
Internal linking is one of the most underutilised SEO techniques. It's entirely within your control and provides significant benefits:
Crawlability and Indexation
- Helps search engines discover all your pages
- Shows the relationship between pages
- Ensures important pages aren't orphaned
PageRank Distribution
- Passes link equity between your pages
- Allows you to prioritise important pages
- Strengthens the authority of key pages
User Navigation
- Improves user experience
- Increases time on site
- Reduces bounce rate
- Guides users through conversion funnels
Topic Clustering Signals
- Demonstrates topical relationships
- Helps establish topical authority
- Shows content depth on subjects
External Links (Outbound)
External links—links from your site to others—affect your SEO too:
Citing Sources (E-E-A-T Signals)
- Demonstrates research and expertise
- Shows you reference authoritative sources
- Supports claims with evidence
User Value
- Provides additional resources for readers
- Enhances content comprehensiveness
- Builds trust through transparency
Relationship Building
- Creates connection with linked sites
- May lead to reciprocal awareness
- Positions you within your industry ecosystem
Link Equity Considerations
- You pass some authority to linked sites
- Strategic external linking doesn't harm you
- Excessive linking to low-quality sites can be problematic
Backlinks (Inbound)
Backlinks remain among the most important ranking factors. Benefits include:
Authority Signals
- Endorsement from other websites
- Votes of confidence in your content
- Cumulative authority building
Referral Traffic
- Direct visitors from linking sites
- Often highly targeted traffic
- Doesn't depend on search rankings
Brand Awareness
- Increases visibility across the web
- Builds recognition in your industry
- Creates presence beyond your own site
Learn more in our complete Backlinks Guide.
Internal Linking Best Practices
Anchor Text Optimisation
Unlike external link anchor text, you have full control over internal link anchors:
Do:
- Use descriptive, keyword-inclusive anchor text
- Vary anchor text naturally (don't use identical text every time)
- Make anchors clearly indicate the destination page
Don't:
- Overuse exact-match anchors artificially
- Use vague anchors like "click here" excessively
- Stuff keywords unnaturally
Good example:
Learn more about [calculating anchor text ratios](/backlinks/anchor-text-ratios)
for your backlink profile, or see our [complete anchor text guide](/backlinks/anchor-text).
Link Depth Management
Keep important pages within 3 clicks of your homepage:
Homepage (Level 0)
└── Category Page (Level 1)
└── Product/Article (Level 2)
└── Related Content (Level 3)
Deeper pages receive less authority and may be crawled less frequently.
Hub and Spoke Structure
Organise content into topic clusters:
Hub page: Comprehensive overview of topic (e.g., /backlinks/) Spoke pages: Detailed pages on subtopics (e.g., /backlinks/anchor-text/)
The hub links to all spokes; spokes link back to the hub and to relevant siblings.
Avoiding Orphan Pages
Orphan pages have no internal links pointing to them. They:
- May not be discovered by search engines
- Receive no internal PageRank
- Often underperform despite good content
Solution: Ensure every page has at least 2-3 internal links pointing to it.
Internal Link Audit
Regularly audit your internal links:
- Identify orphan pages (use Screaming Frog or similar)
- Find pages with few internal links
- Check for broken internal links
- Review anchor text distribution
- Ensure important pages receive adequate links
External Linking Best Practices
Relevance Requirements
Only link to content that genuinely adds value:
- Relevant to your topic
- Actually useful to your readers
- From trustworthy sources
Authority Considerations
Prefer linking to authoritative sources:
- Established publications
- Industry-standard resources
- Primary sources when possible
Avoid linking to:
- Competitor commercial pages (generally)
- Low-quality or spammy sites
- Pages that may disappear
Link Rot Management
External links break over time as pages are removed:
Prevention:
- Link to stable, authoritative pages
- Avoid linking to temporary content
Detection:
- Regularly crawl your site for broken links
- Use monitoring tools to catch issues
Resolution:
- Replace broken links with working alternatives
- Remove links if no alternative exists
NoFollow Considerations
Use rel="nofollow" for:
- User-generated content links
- Paid or sponsored links
- Links to sites you don't fully trust
Standard external links to quality resources can be dofollow.
Affiliate and Sponsored Disclosure
Always properly mark:
- Affiliate links (
rel="sponsored") - Paid placements (
rel="sponsored") - Ads (
rel="sponsored")
See our guide to link attributes for details.
Common Mistakes
Internal Linking Mistakes
Over-linking: Stuffing too many internal links makes content unreadable. Aim for helpful, natural placement.
Identical anchors everywhere: Using exactly the same anchor text for every link to a page looks unnatural.
Linking from footers only: Site-wide footer links are lower value than contextual links within content.
Ignoring new content: New pages often lack internal links. Create a process to add links when publishing.
Random linking: Link to genuinely related content, not just any page on your site.
External Linking Mistakes
Avoiding all external links: This makes content less useful and potentially less trustworthy.
Linking to competitors' commercial pages: Helps them rank for keywords you want.
Ignoring link rot: Broken links harm user experience and can appear neglectful.
Not disclosing paid links: Violates guidelines and can result in penalties.
Backlink Misconceptions
Thinking quantity beats quality: One excellent backlink often outweighs many poor ones.
Ignoring relevance: Links from unrelated sites provide little value.
Over-focusing on metrics: DA/DR are guides, not gospel. Real authority matters.
Tool Recommendations
Internal Linking Tools
Screaming Frog: Crawls your site to analyse internal link structure
Sitebulb: Visual internal linking analysis
Ahrefs Site Audit: Identifies orphan pages and link issues
LinkWhisper (WordPress): Suggests internal linking opportunities
External Link Management
Broken Link Checker: WordPress plugin for finding broken outbound links
Ahrefs Site Audit: Identifies broken external links
Linkody/Morningscore: Monitors outbound link health
Backlink Tools
See our Backlink Audit Guide for comprehensive tool recommendations.
Strategic Integration
Combining All Three Link Types
A strong link strategy integrates all types:
Content Publishing Workflow:
- Write quality content
- Add internal links to relevant existing pages
- Include external citations to authoritative sources
- Promote content to earn backlinks
- Update older content with links to new content
Example integration:
Your new blog post about "email marketing best practices":
- Internal links: Link to your email marketing software page, related blog posts
- External links: Cite industry statistics, reference authoritative guides
- Backlink strategy: Promote post to earn links from marketing publications
Prioritisation
| Link Type | Control Level | Impact | Priority |
|---|---|---|---|
| Internal Links | Complete | Medium-High | High (easy wins) |
| External Links | Complete | Low-Medium | Medium |
| Backlinks | Limited | High | Highest (but hardest) |
Start with internal linking—it's entirely within your control and often underutilised. Build outward from there.
Summary
Understanding the three link types is fundamental to SEO:
Internal Links (your site → your site):
- Within your control
- Distribute PageRank
- Help users and search engines navigate
External Links (your site → other sites):
- Cite sources and add value
- Build relationships
- Should be used thoughtfully
Backlinks (other sites → your site):
- Major ranking factor
- Earned through quality and outreach
- Most valuable but least controllable
Key takeaways:
- Maximise internal linking - It's free and often neglected
- Link out strategically - Add value without helping competitors
- Earn backlinks systematically - The highest-impact, long-term investment
- Audit regularly - All three link types need maintenance
What to Read Next
- Link Equity Explained - How value flows through links
- Complete Backlinks Guide - Master the fundamentals
- Link Building Strategy - Earning backlinks effectively
Find contextual internal links on your site
The internal link opportunity finder scans a sample of your site and returns existing passages that could link to a target page. Review each suggestion for reader value; navigation links alone do not replace useful contextual links.