DNS propagation
Enter a name and a record type. We query the server that is authoritative for the domain and six public resolvers, and tell you who still gives the old value, and for how long.
What "propagation" really means
Nothing propagates in DNS. As soon as you change a record, the server that is authoritative for your domain gives the new value. It is the resolvers (your internet provider's, Google's, Cloudflare's…) that keep the old one in memory, each until the end of its TTL, the caching time you had set.
So the right question is not "has it propagated?" but "who still has the old value, and for how long?". Each resolver's remaining TTL answers it: after that delay, it asks again and sees the new value.
For a change with no waiting
Lower the record's TTL (to 300 seconds, for example) a day before the change, wait for the old TTL to run out, make the change, then raise the TTL again. The switch then takes five minutes instead of several hours.
Record types
| Type | What it is for |
|---|---|
| A, AAAA | the server's IPv4 or IPv6 address |
| CNAME | an alias to another name |
| MX | the servers that receive email |
| TXT | text: SPF, DMARC, ownership verifications |
| NS | the servers that are authoritative for the domain |
| CAA | the authorities allowed to issue a certificate |
What this tool does not do
- It does not see YOUR internet provider's cache: the large public resolvers are queried from our server, not from where you are.
- It does not draw a world map: the large resolvers answer from dozens of cities with the same address, and one question only sees one of them. The TTL, though, is a true bound.
- It changes nothing: to change a record, go to your DNS provider (often your registrar).
Frequently asked questions
How long does DNS propagation take?
At most the TTL of the old record: often an hour, sometimes a day. The "48 hours" you read everywhere date from a time when some internet providers ignored TTLs.
The site still shows the old version for me. What should I do?
Flush your computer's DNS cache, restart the router, or try from your phone on 4G. If the public resolvers already give the new value, only the caches close to you remain.
Why does a resolver answer "query refused"?
Some resolvers filter by the country or network the question comes from. It has nothing to do with your domain: the other resolvers are enough to conclude.
The other tools
Is this site down?
Does the site answer, from our server and from another connection? With the cause when it does not.
What CMS is this site using?
The CMS, the shop, the WordPress theme and the tools a page gives away, with the proof for each.
Who is hosting this website?
Who hosts the pages, who runs the DNS and who handles the email, without mixing them up.
Know when your site's DNS stops answering
A DNS failure makes the site impossible to find for everyone. Expansel checks that your site answers at regular intervals, and emails you as soon as it stops.