# DNS Lookup

> A DNS lookup queries the records that map a domain to its servers. This tool fetches A, AAAA, CNAME, MX, NS, TXT and SOA records in parallel through Cloudflare's DNS-over-HTTPS resolver and shows each value with its TTL.

Source: https://rankcert.com/tools/dns-lookup
Free, no signup. Updated: 2026-08-29

## How to use it

1. Enter a domain name.
2. We query A, AAAA, CNAME, MX, NS, TXT and SOA records in parallel.
3. Read the values and TTLs - a low TTL means a recent or planned change.

## Questions

### What is a TTL?

Time to live, in seconds - how long resolvers may cache the record. Lower it to 300 a day before a migration so the change propagates quickly, then raise it back.

### Why do I see different records than my registrar shows?

You are seeing what public resolvers currently have cached. Immediately after a change, the old value can persist for up to the previous TTL.

### A record or CNAME for the apex?

The DNS spec does not allow a CNAME at the apex alongside other records. Use an A record, or your provider's ALIAS/ANAME flattening if you need to point the apex at a hostname.

### What are the TXT records for?

Domain verification, SPF, DKIM and DMARC. If your email is landing in spam, the SPF and DMARC TXT records are the first place to look.

### How long does DNS propagation take?

Up to the previous TTL of the record, which is why you lower it to 300 seconds a day before a change. There is no global propagation queue - each resolver simply holds its cached copy until it expires.

### What is an SOA record for?

It names the primary nameserver and holds the zone's serial number and refresh timers. A serial that never changes is a sign the zone is not being updated where you think it is.

### Why do MX records have numbers in front?

That is the priority. Lower wins. Mail servers try the lowest-numbered host first and fall back to higher ones, so two records at the same priority load-balance.

### How do I check DNS from a terminal?

dig +short example.com A, or dig example.com MX for mail. Add @1.1.1.1 to query a specific resolver and bypass your local cache.

## Related tools

- [WHOIS Lookup](https://rankcert.com/tools/whois-lookup): Look up any domain's registrar, registration date, expiry, status codes and nameservers using live RDAP registry data.
- [Domain Age Checker](https://rankcert.com/tools/domain-age-checker): Find out exactly how old a domain is, when it was registered, when it was last changed and when it expires.
- [Domain Popularity Checker](https://rankcert.com/tools/domain-rating-checker): Check how popular any domain is on a 0-100 score built from the Tranco top-million ranking, with its raw rank and 30-day movement.
- [Bulk Domain Popularity](https://rankcert.com/tools/bulk-domain-rating): Score up to twenty-five domains at once against the Tranco top-million ranking and sort them, so you can triage a link prospect list in one pass.
- [Bulk Domain Checker](https://rankcert.com/tools/bulk-domain-availability): Check whether 25 domains are registered or free in one pass, straight from the registry over RDAP, with no signup and no upsell to a registrar.
- [Meta Tags Checker](https://rankcert.com/tools/meta-tags-checker): Check any page's title, meta description, canonical, robots and heading structure, and see the exact issues that hurt its rankings.