Free External Link Checker
Outbound links build trust — but a missing rel="noopener" is a security hole. NToolHub's free External Link Checker audits every outbound link in your HTML for security and SEO best practices: noopener on new-tab links, empty anchors and sponsored-link marking. A quick safety pass every editor should run.
How to Use the External Link Checker
- Enter your domain, then paste the page HTML.
- Click Check External Links to list every outbound link.
- Add rel="noopener" wherever target="_blank" is missing it.
- Mark paid links with rel="sponsored" to stay within Google’s guidelines.
Features
Paste HTML plus your domain to isolate external links, then review each with its anchor text, target host and automated flags — missing noopener on target="_blank", empty anchors, plus recognition of properly marked sponsored links.
Benefits & Use Cases
Secure outbound links protect your visitors from tabnabbing attacks, while properly attributed external links (sponsored/ugc where appropriate) keep you compliant with Google's link guidelines and avoid manual actions.
Tips
Add rel="noopener" to every target="_blank" link, mark paid or affiliate links with rel="sponsored", and link out to authoritative sources — relevant outbound links correlate with higher-quality content.
Frequently Asked Questions
Why do external links need rel=noopener?
Pages opened with target="_blank" can access your page via window.opener (tabnabbing attack). rel="noopener" blocks that access. It's a security essential.
Should I nofollow all external links?
No. Nofollow editorial links you'd vouch for — that wastes a natural signal. Use nofollow for untrusted content (comments), sponsored for paid links, ugc for user content.
Do outbound links help SEO?
Linking to authoritative, relevant sources is associated with higher-quality content. There's no direct ranking boost, but it builds reader trust and topical context.
What's tabnabbing?
An attack where the newly opened page redirects your original tab to a phishing copy. rel="noopener" severs the connection between the tabs.
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