DNS Lookup
Look up DNS records for any domain. Query A, AAAA, MX, TXT, NS, CNAME, and SOA records to understand domain configuration.
DNS Lookup
DNS Record Types
A / AAAA
Address records that map domain names to IP addresses
MX
Mail exchange records specifying email servers
TXT
Text records for verification and email authentication
NS
Nameserver records indicating authoritative DNS servers
Common Use Cases
- Verify domain ownership and configuration
- Troubleshoot email delivery issues (MX records)
- Check SPF, DKIM, and DMARC settings (TXT records)
- Find a website's IP address
- Identify hosting providers and CDNs
- Debug DNS propagation after changes
Advanced DNS Records Guide
Security Records
SPF (TXT)
Specifies which servers can send email for your domain.
v=spf1 include:_spf.google.com ~allDMARC (TXT)
Email authentication policy and reporting.
v=DMARC1; p=quarantine; rua=mailto:[email protected]CAA
Certificate Authority Authorization for SSL/TLS.
0 issue "letsencrypt.org"Service Records
SRV
Service discovery for protocols like SIP, XMPP.
10 5 5060 sip.example.comPTR
Reverse DNS lookup for IP to domain mapping.
example.comSOA
Start of Authority with admin and timing info.
ns1.example.com admin.example.comDNS Troubleshooting Guide
Propagation Issues
Symptom: Changes not visible globally
Solution:
- Check TTL values (lower = faster propagation)
- Use multiple DNS checkers worldwide
- Clear local DNS cache
- Wait 24-48 hours for full propagation
Resolution Failures
Symptom: NXDOMAIN or timeout errors
Solution:
- Verify nameserver configuration
- Check domain registration status
- Test with different DNS resolvers
- Validate zone file syntax
Performance Issues
Symptom: Slow DNS response times
Solution:
- Use geographically distributed nameservers
- Optimize TTL values for your use case
- Monitor nameserver performance
- Consider anycast DNS providers
DNS Lookup API
Integrate DNS lookup functionality into your applications with our RESTful API. Perfect for automated monitoring, domain validation, and DevOps workflows.
Quick Start
curl -X GET "https://api.whatismyip.io/dns/lookup?domain=example.com&type=A"Supported Record Types:
Response Example
{
"domain": "example.com",
"type": "A",
"records": [
{
"value": "93.184.216.34",
"ttl": 3600
}
],
"status": "success"
}Developer Use Cases
Domain Validation
Verify domain ownership during user registration or API key provisioning. Check TXT records for verification tokens.
Email Configuration Audits
Automated scanning of SPF, DKIM, and DMARC records to ensure proper email authentication across your organization.
Infrastructure Monitoring
Monitor DNS health and propagation status. Alert when critical records change or become unavailable.
Security Analysis
Detect subdomain takeovers, suspicious TXT records, or unauthorized changes to critical DNS configurations.
CDN & Load Balancer Setup
Verify A/AAAA records point to correct endpoints. Validate geographic distribution and failover configurations.
SSL Certificate Validation
Check CAA records before certificate issuance. Automate domain validation for Let's Encrypt certificates.
Frequently Asked Questions
What is a DNS lookup?
A DNS lookup queries the Domain Name System to retrieve information about a domain, such as its IP addresses (A/AAAA records), mail servers (MX records), or other DNS records like TXT and NS.
What are the different DNS record types?
A records map to IPv4 addresses, AAAA to IPv6, MX specifies mail servers, TXT contains text data (often for verification), NS lists nameservers, CNAME creates aliases, and SOA contains administrative information.
Why would I check MX records?
MX records tell you which servers handle email for a domain. This is useful for troubleshooting email delivery issues, verifying email configuration, or understanding a domain's email infrastructure.
What are TXT records used for?
TXT records store text data and are commonly used for domain verification (Google, Microsoft), SPF email authentication, DKIM signatures, and DMARC policies.
How do I troubleshoot DNS propagation issues?
Check DNS from multiple locations using different DNS servers. Changes can take 24-48 hours to propagate globally. Use online DNS checkers to verify propagation across different geographic regions.
What is DNS caching and why does it matter?
DNS caching stores DNS responses temporarily to improve performance. However, cached records may be outdated during DNS changes. TTL (Time To Live) values control how long records are cached.
How can developers use DNS lookup APIs?
Our DNS lookup API allows programmatic querying of DNS records for applications, monitoring systems, domain validation, and automated DNS health checks. Perfect for DevOps and security automation.