DNS Lookup
Free online DNS lookup tool. Check A, AAAA, MX, TXT, NS, CNAME, SOA and CAA records for any domain in real time. Use as a DNS checker, DNS record lookup tool, MX record lookup, SPF checker, DMARC checker, or nslookup online replacement. Automatically detects and highlights SPF and DMARC records in TXT results. Query all record types at once or select a specific type. Uses DNS-over-HTTPS for real-time results. No login required.
Check DNS Records - A, AAAA, MX, TXT, NS, CNAME, SOA, CAA
Supports A, AAAA, MX, TXT, NS, CNAME, SOA and CAA record types.
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Everything the DNS Lookup Tool Does
How to Use the DNS Lookup Tool
DNS Lookup Tool: LazyTools vs Competitors
Most online DNS checkers work well for basic lookups but few automatically detect and highlight SPF and DMARC records within TXT results or query all record types simultaneously in one request.
| Feature | LazyTools | mxtoolbox.com | dnschecker.org | nslookup.io |
|---|---|---|---|---|
| All record types | Yes (8 types) | Yes | Yes | Yes |
| All types in one query | Yes (parallel) | One at a time | One at a time | One at a time |
| SPF auto-detection | Yes (highlighted) | Yes (separate tool) | No | No |
| DMARC auto-detection | Yes (highlighted) | Yes (separate tool) | No | No |
| TTL displayed | Yes | Yes | Yes | Yes |
| Copy individual records | Yes | No | No | Yes |
| No login required | Yes | Yes | Yes | Yes |
| No ads blocking results | Yes | Heavy ads | Heavy ads | Ads |
DNS Record Types: Complete Reference
DNS (Domain Name System) is the distributed database that maps human-readable domain names to the technical information computers need to connect. Each DNS record type serves a specific purpose.
| Record type | Code | Purpose |
|---|---|---|
| Address | A | Maps domain to IPv4 address (e.g. 93.184.216.34) |
| IPv6 Address | AAAA | Maps domain to IPv6 address (e.g. 2606:2800:220:1:248:1893:25c8:1946) |
| Mail Exchange | MX | Specifies mail servers; includes priority (lower = higher priority) |
| Text | TXT | Arbitrary text; used for SPF, DMARC, DKIM, site verification |
| Name Server | NS | Specifies authoritative DNS servers for the domain |
| Canonical Name | CNAME | Alias pointing one domain to another domain name |
| Start of Authority | SOA | Zone authority record with primary NS, admin email, serial |
| CA Authorization | CAA | Restricts which CAs can issue SSL/TLS certificates for the domain |
MX record lookup: diagnosing email problems
The MX record lookup is the most common reason people use a DNS checker. Email delivery problems almost always trace back to misconfigured MX records. An MX record specifies which mail server accepts email for a domain and its priority. Google Workspace uses aspmx.l.google.com (priority 1) as the primary MX server. Microsoft 365 uses a pattern like domain-com.mail.protection.outlook.com. If your MX records point to the wrong server, email bounces. If priority values are misconfigured, email may not flow correctly to your primary server.
SPF checker: prevent email spoofing
SPF (Sender Policy Framework) records are stored as TXT records and specify which IP addresses and mail servers are authorised to send email from your domain. An SPF record looks like: v=spf1 include:_spf.google.com ~all. The ~all (softfail) mechanism means emails from unlisted servers should be marked as spam. The -all (hardfail) mechanism means they should be rejected outright. This tool automatically detects and highlights SPF records in TXT results, with a blue badge and colour-coded border.
DMARC checker: enforce email authentication
A DMARC record is stored as a TXT record at _dmarc.yourdomain.com and tells receiving servers what to do with emails that fail SPF and DKIM checks. A DMARC record looks like: v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com. The p= policy can be none (monitor only), quarantine (send to spam), or reject (block entirely). This DNS lookup tool automatically queries _dmarc.yourdomain.com when you run a TXT lookup, highlighting the DMARC record with a purple badge.
DNS propagation checker: understanding TTL
DNS propagation is the delay between making a DNS record change and that change being visible worldwide. When you update an A record, the change is instant on your authoritative name server, but other DNS resolvers around the world cache the old record until its TTL (Time to Live) expires. If your A record has TTL 86400 (24 hours), the old record continues to be served for up to 24 hours. To minimise propagation delay before a planned change, reduce the TTL to 300 (5 minutes) at least 24 hours before the change. Then make the change. TTL values are shown for every record in this tool.
nslookup online: the web alternative
nslookup is a command-line tool available on Windows, Mac and Linux for querying DNS records. This DNS lookup tool is the online equivalent - it uses the same DNS-over-HTTPS API that modern DNS resolvers use and returns the same information as nslookup from the command line. The advantage of an online tool is that it always queries from a cloud resolver, so results represent what most internet users see rather than what your local ISP's DNS cache shows.
CAA records: restricting SSL certificate issuance
CAA (Certificate Authority Authorization) records allow domain owners to specify which Certificate Authorities (CAs) are permitted to issue SSL/TLS certificates for their domain. For example, a CAA record with value 0 issue "letsencrypt.org" means only Let's Encrypt can issue certificates. If another CA tries to issue a certificate for your domain, they must check your CAA records and refuse if not listed. CAA records help prevent fraudulent SSL certificate issuance and are required by some browsers for extended validation certificates.