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What could be the issue if my Webflow site with SSL enabled is showing a "Fastly error: unknown domain" message, even though the www domain is correctly registered in the hosting tab?

TL;DR
  • Ensure DNS settings point to Webflow: add a CNAME for www to proxy-ssl.webflow.com and two A records for the root to 75.2.70.75 and 99.83.190.102.
  • Set www as the default domain in Webflow, enable SSL, remove conflicting DNS records, republish the site, and wait for DNS propagation.

The "Fastly error: unknown domain" typically means your domain is not correctly connected to Webflow’s hosting infrastructure. Even if the www domain appears set in Webflow, the error often points to a DNS or domain configuration issue.

1. Verify DNS Settings in Your Domain Registrar

  • Go to your domain registrar (e.g., GoDaddy, Google Domains).
  • Make sure that your DNS records are pointing to Webflow’s servers:
  • For www.yourdomain.com, add a CNAME record pointing to proxy-ssl.webflow.com.
  • For the root domain (e.g., yourdomain.com), add two A records pointing to:
    • (a) 75.2.70.75
    • (b) 99.83.190.102
  • Do not use a CNAME or redirect for the root domain, as some DNS providers don’t support it — use the A records instead.

2. Ensure WWW Version is Set as the Default Domain

  • In Webflow > Project Settings > Hosting tab, check the Default Domain.
  • Make sure www.yourdomain.com is set as the default (indicated with a checkmark).
  • If not, click the “Make default” next to the correct domain.

3. Wait for DNS Propagation

  • Changes to DNS can take up to 48 hours to fully propagate, though most settle within a few hours.
  • During this time, your site might intermittently show the Fastly error.

4. Remove Any Conflicting DNS Records

  • Look for and remove any old or third-party DNS records, such as:
  • Other A records not pointing to Webflow
  • Conflicting CNAME records
  • There should only be one CNAME for www and the two specified A records for the root.

5. SSL Configuration in Webflow

  • In the Hosting tab, make sure SSL is enabled.
  • If you recently enabled SSL, try turning it off and back on, then republish the site.

6. Republish Your Webflow Site

  • After confirming all settings, click “Publish to selected domains” in Webflow.
  • This ensures Webflow regenerates the correct SSL certificate and serves your content properly.

Summary

To fix the Fastly "unknown domain" error, ensure your DNS settings match Webflow’s required A and CNAME records, confirm that the www version is the default domain, republish your site, and allow time for DNS propagation. This resolves most domain connection issues.

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