In this guide · 7 sections
Short answer
A changed DNS record usually updates within the record's TTL, often 5 minutes to 1 hour. Nameserver changes take longer: up to 24 hours at the registrar, plus the parent zone's cache, which is 48 hours for .com but 1 hour for .sg. If it is still wrong after 48 hours, it is probably misconfigured.
Why DNS changes take time: TTL and caching
When someone visits your site, their device asks a DNS resolver (usually their ISP's, or Google's 8.8.8.8 or Cloudflare's 1.1.1.1) for your domain's records. The resolver keeps the answer for as long as the record's TTL (time to live) says, then asks again. Until that cached copy expires, it keeps handing out the old answer.
Cloudflare's TTL documentation puts it simply: a longer TTL speeds up lookups but means updates take longer to reach your users. Cloudflare sets proxied records to 300 seconds, while DNS-only records can be set from 60 seconds to a day. It also notes that your own computer's cache can take longer than the TTL to update.
So 'propagation' is really thousands of caches expiring at different times. Someone whose resolver fetched the old record a minute before your change waits the full TTL; someone else sees the new record immediately.
How long DNS propagation takes, by type of change
The wait depends on which layer you changed.
| What you changed | Typical wait | What controls it |
|---|---|---|
| A, CNAME or TXT record | Minutes to the old TTL (often 5 min to 1 hour) | The TTL that was on the old record |
| MX record (email) | Up to the old MX TTL | Old TTL; some senders retry for hours |
| Nameservers on a .sg domain | Registrar processing plus about 1 hour | Registrar, then .sg parent NS TTL (3,600 s) |
| Nameservers on a .com domain | Registrar processing plus up to 48 hours | Registrar, then .com parent NS TTL (172,800 s) |
| New domain just registered | Usually minutes to hours | Registrar and registry publishing; .sg also needs VerifiedID within 21 days |
Two details trip people up. First, the TTL that matters is the one on the old record, because that is what resolvers cached. Lowering the TTL at the same moment you change the value does not help anyone who cached it an hour ago. Second, for nameserver moves, Cloudflare's set-up guide tells users to wait up to 24 hours while the registrar updates the nameservers, before any caching even starts.
How to check DNS propagation
Check from more than one place, and check the authoritative answer as well as cached ones.
Ask the authoritative nameserver
Find your domain's nameservers (any WHOIS or NS lookup) and query them directly, for example with dig @ns1.yourprovider.com yourdomain.sg A. If the authoritative answer is wrong, waiting will not fix it.
Ask two public resolvers
Query Google (8.8.8.8) and Cloudflare (1.1.1.1). If both show the new value, most of the world will soon too.
Use a global propagation checker
These tools query resolvers in many countries and show which still return the old value. Expect a mix during the TTL window.
Flush caches you control
Google Public DNS has a Flush Cache page for a specific name. Clear your computer's DNS cache, or test on mobile data.
Test the service, not just the record
Load the site in a private window, check the SSL certificate is for the right host, and send a test email in both directions after MX changes.
When it is not propagation: signs of a misconfiguration
If the TTL has passed and the old answer is still coming back from the authoritative servers, something is set up wrong. These are the usual culprits.
Misconfiguration checklist
The DNSSEC point is easy to miss. Cloudflare warns that you must turn DNSSEC off at the registrar before replacing nameservers, because changing nameservers with DNSSEC still active can cause resolution failures. For an expired domain, see our domain expired guide; for which record does what, see DNS records explained.
Changing DNS without breaking email or the website
Most DNS incidents in small businesses happen during a website move: someone points the domain at a new host or nameservers and forgets that email records lived in the old DNS zone.
- Copy the whole zone first. Before switching nameservers, recreate every record at the new provider: MX, SPF, DKIM, DMARC, verification TXT records and any subdomains.
- Change one thing at a time. Move the website, confirm it, then touch email, or the reverse.
- Expect a mixed period. During the TTL window some visitors reach the old host and some the new one, so keep the old site running until traffic stops.
- Check email both ways. MX changes can mean a few hours where some senders deliver to the old server.
Our guides on changing MX records without downtime and connecting a domain to a website without breaking email walk through both moves step by step.
Do it yourself or get help?
Waiting out a TTL needs no help, and checking with two public resolvers tells you most of what you need. Get help if the authoritative answer is wrong and you cannot see why, if email has stopped, or if you are about to move nameservers on a domain that carries both website and email.
IT Sorted's Domain & DNS Setup (S$99) registers or transfers the domain in your name and points the website and email records correctly, with SSL and renewal checked. For a single stuck record or a quick diagnosis, a Quick Fix (S$119) covers up to an hour of remote work with a written summary.
Frequently asked questions
Sometimes, but not usually. A simple record change typically shows within the old record's TTL, often minutes to an hour. The 48-hour figure comes from nameserver changes on domains like .com, where the registry caches nameserver records for 48 hours. For .sg, the registry's nameserver TTL was one hour when we checked in October 2026.
Your resolver fetched the new record, while your customer's resolver still has the old one cached until its TTL expires. It is also common for your own browser or computer to keep an old answer longer. Ask them to try mobile data or a private window, and wait out the TTL.
You cannot force other resolvers to drop their cache, but you can plan ahead by lowering the TTL a day before the change. After the change, you can flush Google Public DNS for that name, clear your own computer's cache, and test on mobile data to see the new value sooner.
Query your domain's authoritative nameservers directly. If they return the old or wrong value, waiting will not help; the record is wrong or you edited the wrong DNS provider. If they return the right value but some resolvers do not, it is caching and will clear after the TTL.
A newly registered .sg domain usually starts resolving within minutes to hours, depending on the registrar. Remember the separate VerifiedID@SG requirement: the administrative contact must verify within 21 calendar days, or SGNIC suspends the domain and it stops resolving entirely.