~/dnsniffer/tlds/ac.jp·rank #722
▸ How many .ac.jp domains are registered?
3,336
active .ac.jp domains as of .
# rank #722 of all TLDs ▲ 5 in 30d# all records held: 3,430# snapshots: 20
~/tlds/ac.jp/history·active domains
3,336
active .ac.jp domains on 2026-09-05 · ▲ +2,517 (+307.33%) since 2025-06-30
# y-axis starts at 516.12, not zero - domain counts move by fractions of a percent a day. Dashed segments are estimated: reconstructed from certificate first-seen dates before daily snapshots began, not measured on the day.
# change over time
30 days
▼ -0.21%
-7 domains
90 days
▲ +0.36%
+12 domains
1 year
▲ +3.41%
+110 domains
# faq
- ? How many .ac.jp domains are registered?
- There are 3,336 active .ac.jp domains as of September 5, 2026, according to DNSniffer’s daily count of zone-file and certificate-transparency records.
- ? Is .ac.jp growing or shrinking?
- .ac.jp has grown by 3.41% over the last year (+110 domains).
- ? Where does the .ac.jp domain count come from?
- We ingest ICANN CZDS zone files and Certificate Transparency logs continuously and snapshot the per-TLD count once a day. A .ac.jp domain is counted as active if it appeared in a zone file in the last 2 days, or - where no zone file is published - if a certificate was issued for it in the last 12 months.