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CNAME Lookup

Look up the CNAME (canonical name) record on any DNS name. CNAMEs alias one name to another. Common in custom-domain wiring (e.g. www.example.com → example.web.app), ESP DKIM CNAME chains (e.g. selector._domainkey.example.com), and CDN setups.

CNAMEs are forbidden at the DNS apex (e.g. example.com); look them up on subdomains.

When to use this

  • Custom-domain hosting: verify your www CNAME points at the right hosting provider.
  • DKIM via CNAME: ESPs like Mailchimp, Postmark, and SendGrid issue DKIM as CNAME records you publish at selector._domainkey.yourdomain.
  • Custom email subdomain: Resend / SES setup often involves CNAMEs at send.r1.yourdomain or similar.
  • SaaS sub-domain: tools like Notion, Webflow, and Vercel hand you a CNAME target to point your custom domain at.