DNS Propagation Checker

DNS Propagation Checker

After you change a DNS record, resolvers around the world keep serving the old answer until their cached copy expires. This checker asks about 30 public resolvers at the same time, grouped by region (North America, Europe, Asia, Oceania, South America, Africa, plus global services such as Cloudflare, Google, Quad9 and OpenDNS), and shows what each one returns right now.

What You Can Check

• IP: the domain's A record (IPv4 address). Use it after moving a site to a new server.
• Nameserver: the domain's NS records. Use it after moving DNS hosting, for example from your registrar to Cloudflare.

At the bottom, the tool tells you whether every resolver that answered gave the same result. Resolvers that time out (each gets 3 seconds) don't appear in the list.

Why Changes Take Time

DNS doesn't push updates. Each resolver caches an answer for the record's TTL (time to live) and asks again only after it expires. If your old A record had a TTL of 3600, some resolvers keep returning the old IP for up to an hour after you change it. Name server changes take longer, because the TLD's own NS records for your domain often have a TTL of one or two days.

To speed up a planned move, lower the record's TTL to 300 a day before the change. Raise it again once the new value shows everywhere.

Reading the Results

• A mix of old and new values: normal during the first TTL period after a change. Check again later.
• Different IPs that are all correct: sites behind a CDN or with several A records often return different addresses by location or in rotating order. The tool compares the first address each resolver returns, so these sites can show as "unsuccess" when nothing is wrong.
• Old value everywhere after a long wait: check that you edited the zone at the DNS host your NS records point to. Editing records at a registrar that doesn't host your DNS changes nothing.

Your own computer and browser cache DNS too. If the checker shows the new value but your browser doesn't, flush the local cache (ipconfig /flushdns on Windows, sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder on macOS) or try another network. To see the records your DNS host serves, query it directly with the DNS record lookup.