DNS Lookup Tool
Free client-side DNS-over-HTTPS lookup tool with A, AAAA, MX, TXT, NS, CAA records, SPF/DMARC checks, and DNSSEC validation.
| Host | TTL | IP Address / Data | Action |
|---|---|---|---|
github.com. |
60s | 140.82.112.3 |
| Host | TTL | Priority & Mail Server | Action |
|---|---|---|---|
github.com. |
3600s | Priority 10 → aspmx.l.google.com. |
| Host | TTL | TXT Content | Action |
|---|---|---|---|
github.com. |
3600s | "v=spf1 include:_spf.google.com ~all" |
|
github.com. |
3600s | "MS=ms65749363" |
| Host | TTL | Authoritative Name Server | Action |
|---|---|---|---|
github.com. |
900s | dns1.p08.nsone.net. | |
github.com. |
900s | dns2.p08.nsone.net. | |
github.com. |
900s | ns-1283.awsdns-32.org. | |
github.com. |
900s | ns-1707.awsdns-21.co.uk. |
Standard DNS Record Types & Protocol Reference
Understanding DNS record taxonomy helps prevent routing loops, mail deliverability blacklists, and certificate issuance failures.
| Type | RFC Standard | Core Function | Example Target |
|---|---|---|---|
| A | RFC 1035 | Maps a domain name directly to a 32-bit IPv4 address | 192.0.2.1 |
| AAAA | RFC 3596 | Maps a hostname to a 128-bit IPv6 address | 2606:4700:4700::1111 |
| CNAME | RFC 1035 | Canonical alias pointing one hostname to another canonical name | app.example.com → cdn.cloudflare.net |
| MX | RFC 5321 | Specifies incoming mail exchange servers with priority ranks | 10 mail.example.com |
| TXT | RFC 1464 | Human and machine-readable text (SPF, DKIM, site verification) | v=spf1 include:_spf.google.com ~all |
| CAA | RFC 8659 | Restricts which Certificate Authorities may issue TLS certs | 0 issue "letsencrypt.org" |
About this tool
How to use it
- Type any domain hostname (e.g., 'github.com', 'cloudflare.com', 'google.com') into the lookup field.
- Select a specific record type (A, AAAA, CNAME, MX, TXT, NS, SOA, CAA) or choose 'All Essential Records'.
- Select your preferred privacy-preserving resolver: Cloudflare (1.1.1.1) or Google Public DNS (8.8.8.8).
- Inspect parsed record answers, TTL expiration timers, priority values, and DNSSEC validation flags.
- Review automated email security audits checking SPF, DMARC, and CAA certificate issuer policies.
Why it matters
Network engineers, webmasters, and developers frequently need to verify DNS propagation, debug email delivery failures (SPF/DMARC/MX), and audit server routing. This tool queries authoritative DoH endpoints directly from your browser with zero server intermediaries or query logging.
When to use it
Use when migrating DNS to a new host, configuring Cloudflare or AWS Route 53, debugging mail bouncebacks, validating SSL certificate issuance (CAA), or auditing DNSSEC signatures.
Common questions
How does this tool perform DNS lookups directly from the browser?
Browsers cannot make raw UDP port 53 sockets. Instead, this tool uses RFC 8484 DNS-over-HTTPS (DoH) JSON APIs provided by Cloudflare (1.1.1.1) and Google (8.8.8.8). Responses are cryptographically verified and returned over secure HTTPS.
What is TTL (Time to Live)?
TTL specifies the number of seconds intermediate DNS resolvers and client caches may cache the record before making a fresh authoritative query. A low TTL (300s / 5 mins) is ideal during migrations, while higher TTLs (86400s / 24h) reduce latency.
What do MX priorities mean?
MX (Mail Exchange) records include a preference number. Mail transfer agents attempt delivery to the server with the lowest preference number first (e.g. priority 10 before priority 20).
Why is CAA (Certification Authority Authorization) important?
CAA records prevent unauthorized certificate authorities from issuing SSL/TLS certificates for your domain. For example, a CAA record specifying 'issue letsencrypt.org' stops rogue or compromised third-party CAs from issuing certificates.