External Link Monitoring: Why Third-Party Link Health Matters
The Hidden Risk of External Links
Every website relies on external resources. Your site probably links to:
- CDN-hosted libraries (jQuery, Bootstrap, fonts)
- Partner and affiliate sites
- Social media profiles
- Documentation and resource links
- Third-party APIs and widgets
When these external links break, your users suffer—but traditional internal link checking ignores them entirely.
What Can Go Wrong?
Partner Site Changes
That affiliate link you added two years ago? The partner may have:
- Restructured their URL paths
- Changed their domain
- Gone out of business
- Moved to a new platform
CDN Outages and Deprecations
- Google Fonts occasionally deprecates old font families
- CDN providers sunset older library versions
- jQuery 2.x URLs now redirect (or fail)
Social Media Profile Changes
- Company rebrands and changes handles
- Platform URL structures change
- Profiles get suspended or deleted
Resource Link Rot
Studies show that approximately 10% of links break each year. Documentation, blog posts, and reference materials you linked to may simply vanish.
How External Link Monitoring Works
Automatic Discovery
When our crawler scans your pages, it identifies both internal and external links. External links are flagged based on:
- Different domain than your primary URL
- Absolute URLs pointing to other sites
- CDN and asset URLs from third parties
Selective Monitoring
Not every external link needs monitoring. You can:
- Enable/disable per link: Monitor critical dependencies, skip low-priority links
- Set per-monitor limits: Pro plan allows 100 external links per monitor; Enterprise is unlimited
- View separately: External link status is reported separately from internal links
Same Great Alerting
External links use the same notification system:
- Email, Slack, and Discord alerts
- Configurable failure thresholds
- Include in daily summary reports
Use Cases
E-Commerce Product Links
You link to manufacturer product pages from your catalog. When manufacturers reorganize their sites, your product links break—customers click through to 404 pages, and you lose sales.
Solution: Monitor manufacturer links for each product category. Get alerted when any break so you can update them promptly.
Documentation Sites
Your developer docs reference:
- GitHub repositories
- Stack Overflow answers
- Third-party API docs
- Tutorial blog posts
These external references break constantly as the web evolves.
Solution: Enable external monitoring on your docs site. Prioritize links to official documentation over community posts.
Affiliate and Partner Programs
Affiliate links are revenue generators. A broken affiliate link means:
- Lost commissions
- Poor user experience
- Wasted marketing traffic
Solution: Monitor all affiliate URLs. Set up Slack alerts for immediate notification when any partner link fails.
Getting Started
For Pro Users
- Open any monitor in your dashboard
- Navigate to the “External Links” tab
- Review discovered external links
- Toggle monitoring on for critical links
- Configure alert preferences
Note: Pro plan includes 100 external links per monitor. Prioritize your most important dependencies.
For Enterprise Users
Enterprise plans include unlimited external links per monitor. Enable monitoring on all external dependencies without worrying about limits.
For Free Plan Users
External link monitoring is available on Pro and Enterprise plans only. Upgrade to start monitoring your external dependencies.
Best Practices
Prioritize by Business Impact
Focus monitoring on:
- Revenue-generating links (affiliates, partner programs)
- Critical dependencies (CDNs, required APIs)
- User-facing links (social profiles, contact forms)
- Legal requirements (privacy policy links, terms pages)
Set Realistic Expectations
External sites are outside your control. Some things to consider:
- Rate limiting: Some sites may block repeated checks; we use respectful intervals
- Geo-restrictions: A link might work in some regions but not others
- Temporary issues: External sites have their own uptime challenges
Regular Review
External links should be audited quarterly:
- Remove links to defunct sites
- Update links that have moved
- Consider replacing unreliable external dependencies with self-hosted alternatives
Plan Comparison
| Feature | Free | Pro | Enterprise |
|---|---|---|---|
| External link discovery | ✅ | ✅ | ✅ |
| External link monitoring | ❌ | 100/monitor | Unlimited |
| Alert notifications | ❌ | ✅ | ✅ |
| Separate reporting | ❌ | ✅ | ✅ |
FAQ
Q: Do external links count against my check quota?
A: External links are checked during the same crawl cycle as internal links. They don’t add extra checks but are subject to plan limits.
Q: Can I monitor any external URL?
A: We monitor URLs that appear as links on your website. You can’t add arbitrary external URLs—they must be discovered during normal crawling.
Q: What about paywalled or authenticated external sites?
A: We check external links as an anonymous user. If a link requires authentication, we’ll report the status code we receive (often 401 or 403).
Q: How often are external links checked?
A: External links follow the same rotation as internal links, checked based on your monitor’s interval and the oldest-first scheduling algorithm.