Outbound links are an SEO and security check at once
Outbound links (links from your page to other domains) signal topical context to Google, can leak link equity if not managed, and create security risks if used carelessly. This checker audits every external link, reporting domain, rel attributes, and target behavior.
Key metrics: total outbound link count, unique domains, nofollow usage, and unsafe target="_blank" links. The last is a security issue (tabnabbing) that affects 30 to 50% of sites we audit.
Tabnabbing: the unsafe target="_blank" risk
When a link uses target="_blank" without rel="noopener", the page that opens in the new tab gets access to window.opener, which is a reference back to your tab. The opened page can then redirect your tab to a phishing URL while users believe they are still on your site. This is called tabnabbing.
Modern browsers default to noopener for cross-origin links opened with target="_blank", but this is recent behavior and not universal. Always set rel="noopener noreferrer" explicitly. The fix is one attribute and prevents the entire attack class.
Nofollow on outbound links
Nofollow tells Google not to pass link equity through this link. Use it for: paid links (legally required), affiliate links (FTC disclosure plus SEO best practice), user-generated content where you cannot vouch for the destination, and links to known low-quality or spammy sites.
Do not use nofollow on every outbound link. Linking generously to authoritative sources is a quality signal. Sites that hoard all link equity by nofollowing everything externally rank worse than sites that link liberally to good sources.
The newer rel attributes: sponsored and ugc
Since 2019, Google supports rel="sponsored" for paid links and rel="ugc" for user-generated content. Both are treated similarly to nofollow for ranking purposes, but provide more accurate attribution to Google.
Use sponsored on affiliate links, paid placements, and anything an advertiser influenced. Use ugc on links posted by users in comments, forums, or community sections. Use nofollow as a fallback for links you do not want to vouch for but that do not fit either of the above.
Outbound link best practices
Link to authoritative sources for facts, statistics, and claims. This signals due diligence to both Google and AI search systems, which use citation patterns to evaluate content quality.
Open external links in the same tab unless there is a clear UX reason not to (forms, applications, complex multi-step workflows). Forcing target="_blank" on all external links makes back-button behavior weird and clutters tab history.
For e-commerce or affiliate-heavy sites, audit the outbound:inbound link ratio. Sites that link out 100x more than they link internally signal "thin affiliate" patterns to Google. Healthy sites have a balance.