Quickly confirm the current return value of a specific record type, and compare with propagation check results.
Free online DNS lookup tool. Enter a domain to query 7 DNS record types: A/AAAA/CNAME/MX/TXT/NS/SOA. Backend queries without CORS restrictions, displays TTL and MX priority, supports one-click copy.
DNS (Domain Name System) is the internet's "phone book", translating human-readable domain names (like example.com) into machine-readable IP addresses. Looking up DNS records allows you to: 1) Confirm if domain resolution is working; 2) Troubleshoot website accessibility issues; 3) Verify MX/TXT email configurations are correct; 4) Check if CDN switches or domain migrations are complete; 5) Confirm SPF/DKIM/DMARC security records are configured.
The reason is usually DNS caching: your local computer, router, and ISP recursive DNS servers all cache DNS records, returning cached results instead of new values within the TTL period. After changing DNS records, nodes need to wait for TTL expiration to see new values. This tool queries from backend public DNS nodes, bypassing local/ISP caching to show the latest authoritative resolution results.
A records map domains to IPv4 addresses (e.g., 192.0.2.1), while AAAA records (also called IPv6 address records) map domains to IPv6 addresses (e.g., 2001:db8::1). Modern websites typically configure both A and AAAA records for dual-stack IPv4/IPv6 access. AAAA is 4 times the length of A (IPv6 addresses are 128-bit vs IPv4's 32-bit), hence the name "quad-A" record.
Root domains (like example.com, without www) cannot use CNAME (CNAME blocks other record types, violating RFC specifications) and must use A/AAAA records. Subdomains (like www, cdn, api) can use CNAME to point to another domain (common in CDN scenarios, e.g., www.example.com → example.cdn.cloudflare.com). Domains with MX, NS, or SOA records also cannot have CNAME records.
Smaller priority/preference numbers in MX records indicate higher priority. When sending email, the smallest numbered MX server is tried first; if connection fails, other MX servers are tried in ascending numerical order. Common configuration: primary MX set to 10, backup MX set to 20; multiple servers with equal priority can use the same number (load balancing). Don't set only one MX server, as single point of failure will prevent email delivery.
TXT records are the most flexible DNS record type, with common uses including: 1) SPF records: specify servers allowed to send email, preventing forged emails; 2) DKIM: email digital signature public keys; 3) DMARC: email policy reporting; 4) Domain ownership verification (Google Search Console, SSL certificate issuance, Apple developer verification, etc.); 5) Arbitrary custom text.
TTL (Time To Live) is the caching duration for DNS records on recursive DNS servers, measured in seconds. After modifying DNS, the "propagation time" depends on the previous TTL setting: records with TTL=3600 (1 hour) take up to 1 hour to propagate globally; TTL=300 (5 minutes) propagates within 5 minutes. It is recommended to lower TTL to 300 seconds 24-48 hours before switching/migration, then restore normal TTL after completion. Note: cache refresh times vary across ISP recursive DNS servers; complete global propagation may take longer.
DNS lookup is the process of requesting resolution records for a specific domain from DNS servers, and is one of the most fundamental internet operations - every website visit, email send, or API connection triggers DNS lookups behind the scenes. DNS records come in many types; the most commonly used include: A (IPv4 address), AAAA (IPv6 address), CNAME (alias), MX (mail server), TXT (text/verification/security policy), NS (DNS server), SOA (zone authority), etc.
**Why use an online DNS lookup tool?** Your local computer, browser, operating system, router, and ISP recursive DNS servers all cache DNS records (cache duration controlled by TTL), so what you see locally may be stale cached values. After modifying DNS records, you need a lookup tool independent of your local environment to confirm new records have taken effect on authoritative DNS. This tool performs direct recursive queries from backend public DNS nodes, **bypassing local/ISP caching** to return current authoritative resolution results.
**Common DNS lookup scenarios**: Confirm A/AAAA records point to correct IP when a website is unreachable; verify resolution after CDN switches/server migrations; check MX records and priorities after configuring business email (Google Workspace/Office 365, etc.); verify TXT records after configuring SPF/DKIM/DMARC anti-spam policies; check verification TXT records during domain ownership verification (Google Search Console, SSL issuance, Apple Developer).
**Core usage of each record type**: A/AAAA are the most basic address records; CNAME is used for subdomain aliases (common in CDN scenarios, but cannot be used at root domain); MX includes priority and determines mail delivery paths; TXT is the "Swiss Army knife" record for SPF/DKIM/DMARC/domain verification; NS specifies which DNS server is authoritative; SOA records zone version, primary NS, admin email, and refresh parameters.
This tool **supports 7 most commonly used DNS record types** (A/AAAA/CNAME/MX/TXT/NS/SOA). Backend DNS queries are not affected by browser CORS restrictions or local caching, automatically extracting each record's value, TTL, and additional information (like MX priority). Supports quick switching between recent lookups, preset quick examples, and one-click copying of summaries/record lists/raw JSON.
| Record Type | Type ID | Purpose | Example |
|---|---|---|---|
A | 1 | Maps domain to IPv4 address | example.com → 93.184.216.34 |
AAAA | 28 | Maps domain to IPv6 address | example.com → 2606:2800:220:1:: |
CNAME | 5 | Alias record pointing to another domain | www.example.com → example.com |
MX | 15 | Mail server address and priority | 10 mx.example.com |
TXT | 16 | Text records (SPF/DKIM/DMARC/verification) | v=spf1 include:_spf.google.com ~all |
NS | 2 | Specifies authoritative DNS servers for domain | ns1.example.com |
SOA | 6 | Start of authority, contains primary NS/email/serial | ns1.example.com admin.example.com 2024010101 |
PTR | 12 | Reverse lookup (IP → domain) | 34.216.184.93.in-addr.arpa → example.com |
CAA | 257 | Specifies CAs allowed to issue certificates | 0 issue "letsencrypt.org" |
SRV | 33 | Service location (e.g., SIP/XMPP/LDAP) | _sip._tcp.example.com |
| Scenario | Recommended TTL | Notes |
|---|---|---|
| Stable production (normal) | 3600 seconds (1 hour) | Balances caching efficiency and change flexibility |
| Upcoming switch/migration | 300 seconds (5 minutes) | Lower 24-48 hours before switch to reduce cache refresh time |
| During switch process | 60 seconds (1 minute) | Enables quick rollback; restore normal TTL after switch |
| CDN/high availability | 300-600 seconds | Balances failover speed and DNS query load |
| MX mail records | 3600-86400 seconds (1h-1d) | Mail records rarely change; longer TTL is acceptable |
| NS records | 86400 seconds (1 day) | NS changes very rarely; long TTL improves resolution efficiency |
| Provider | Primary DNS | Secondary DNS | Features |
|---|---|---|---|
| Google Public DNS | 8.8.8.8 | 8.8.4.4 | Global nodes, fast speeds, supports DNS-over-TLS |
| Cloudflare 1.1.1.1 | 1.1.1.1 | 1.0.0.1 | Privacy-first, fastest globally, supports DoH/DoT |
| OpenDNS | 208.67.222.222 | 208.67.220.220 | Security filtering, phishing protection, parental controls |
| Quad9 | 9.9.9.9 | 149.112.112.112 | Security protection, automatic malicious domain blocking |
