DNS is the internet's phone book — translating human-readable domains into IP addresses. When your site goes down, email stops working, or SSL verification fails, DNS misconfiguration is often the culprit. Understanding DNS records is fundamental infrastructure knowledge.
What Is DNS Lookup?
DNS (Domain Name System) stores records that map domain names to various resources. Our DNS Lookup queries all record types for any domain and explains what each record does.
How to Use DNS Lookup on DevToolHub
- Open the DNS Lookup tool on DevToolHub — no signup required.
- Paste or enter your input data in the left panel.
- See the result instantly in the output panel.
- Copy the result or download it as a file.
Essential DNS Records
The records every developer should know:
// A Record — maps domain to IPv4 address
example.com → 93.184.216.34
// AAAA Record — maps domain to IPv6
example.com → 2606:2800:220:1:248:1893:25c8:1946
// CNAME — alias to another domain
www.example.com → example.com
blog.example.com → example.ghost.io
// MX — mail server (with priority)
example.com → 10 mail.example.com
20 backup-mail.example.com
// TXT — verification and policy
example.com → "v=spf1 include:_spf.google.com ~all"
"google-site-verification=abc123..."Pro Tips
- DNS changes propagate in 1-48 hours — lower TTL before planned changes to speed propagation
- Use CNAME for subdomains but never for the root domain (use A/ALIAS instead)
- MX records need priority values — lower numbers have higher priority
- TXT records handle SPF (email auth), DKIM, domain verification, and more
When You Need This
- Debugging website DNS configuration and propagation issues
- Setting up email delivery with proper MX, SPF, and DKIM records
- Verifying domain ownership for SSL certificates and services
- Migrating domains between hosting providers
Free Tools Mentioned in This Article