Japan DNS Propagation Checker
Run a DNS lookup against 6 resolvers located in Japan — Tokyo · Chiyoda City · Tokyo · Osaka · Koishikawa · Gotenba Shi.
- Resolved
- No answer
- Checking
-
Tokyo
Japan
—
-
Chiyoda City
Japan
—
-
Tokyo
Japan
—
-
Osaka
Japan
—
-
Koishikawa
Japan
—
-
Gotenba Shi
Japan
—
What checking DNS from Japan tells you
A DNS resolver keeps a cached copy of each record for as long as its time-to-live allows, and does so separately in every location. A change you have published can be live on one resolver while another still serves the old answer.
Checking from Japan looks up the record on servers inside the country, so you see what people there actually get rather than what a resolver on another continent returns.
This matters most right after you edit a record: an update visible on a global resolver like 8.8.8.8 can still be stale at a local ISP in Japan until its cached copy expires. The check confirms the new value has reached the resolvers your Japan visitors depend on.
Japan runs one of the most self-contained internets in the world. Domestic traffic overwhelmingly stays domestic, exchanged in Tokyo and Osaka, and NTT's networks carry a share of it that few single operators anywhere can match.
Japanese users are also further along on IPv6 than most countries, which means checking your AAAA records from Japan is not optional the way it might be elsewhere: a broken IPv6 answer nobody notices in other markets will be noticed here.
Add the usual CDN behaviour, where a Tokyo resolver is steered to a Tokyo edge, and a check from inside Japan tells you two specific things: whether Japanese caches hold your latest records, and whether your site presents a working IPv6 face to the users most likely to use it.
- NTT Communications Default for a large fraction of households
- Internet Multifeed Tokyo operator behind the JPNAP exchange
How DNS propagation works
Every DNS record carries a time-to-live: the seconds a resolver may keep its cached answer before asking again. Change a record and resolvers holding the old value keep serving it until that timer runs out.
Propagation is this expiry playing out across many independent resolvers, so a lower time-to-live set ahead of a change makes it take effect sooner. There is no fixed waiting period — each record's time-to-live decides how long the old answer lingers.
Frequently Asked Questions
Why do DNS servers in Japan return different results than 8.8.8.8?
Two things cause it. Each resolver caches independently, so one can hold an older answer than another.
And content delivery networks reply based on where the asking resolver is, steering a resolver in Japan toward a nearby edge node.
Both answers can be correct at the same time for their own location.
How long until a DNS change is visible in Japan?
It depends on the record's time-to-live, not on the country.
Resolvers in Japan keep the previous answer until their cached copy expires, then pick up the new one.
If you lowered the time-to-live before making the change, it appears sooner; otherwise the old value can persist until the original timer elapses.
Which DNS server should users in Japan use?
For most people the resolver their internet provider assigns is fine and usually the lowest latency.
Anyone who wants an alternative can point to a public resolver reachable from Japan, such as Cloudflare (1.1.1.1) or Google (8.8.8.8); the right choice depends on whether you value speed, privacy, or filtering.
Why check DNS from Japan specifically?
Because it shows what visitors in Japan actually resolve, which can differ from a global lookup.
If your audience is in Japan, or you have moved hosting or mail there, checking against in-country resolvers confirms the records have reached the servers those users rely on.
Should I check AAAA records separately for Japan?
Yes. Japanese IPv6 adoption is among the highest anywhere, driven by NTT's fiber network, so a meaningful share of your Japanese visitors will prefer the AAAA record when one exists. If it points somewhere stale or unreachable, those users suffer while your IPv4-only checks stay green.
Why do Tokyo and Osaka resolvers return different CDN addresses?
Large CDNs keep separate edge capacity in both cities and hand each resolver the closer one. Both answers are correct. If you see a non-Japanese address from either city, that is the more interesting result, since it means Japanese users are being served from abroad.
