IONOS / 1&1
Registrar DNS Serves 4,232,905 legacy-gTLD domains across 17 TLDs, 3.37% of all domains whose nameservers we can attribute. www.ionos.com/
How domains are attributed here
A domain counts towards IONOS / 1&1 when one of its nameservers ends in one of these suffixes. Matching is on the name in the zone's NS records only — nothing is resolved or fetched. Listed by weight, which is the order the classifier tries them in so a specific suffix beats a broader one.
| Nameserver suffix | Weight |
|---|---|
| 1and1-dns.com | 10 |
| ui-dns.biz | 10 |
| ui-dns.com | 10 |
| ui-dns.de | 10 |
| ui-dns.org | 10 |
Where its domains are
Source: Daily zone files
| .com | 3.22M | 76.09% |
|---|---|---|
| .org | 390.61k | 9.23% |
| .net | 285.89k | 6.75% |
| .info | 284.05k | 6.71% |
| .biz | 27,659 | 0.65% |
| .name | 7,937 | 0.19% |
| .pro | 7,584 | 0.18% |
| .cat | 4,490 | 0.11% |
| .mobi | 3,067 | 0.07% |
| .asia | 643 | 0.02% |
| Other7 more TLDs | 150 | <0.01% |
The ten largest of 17 TLDs, with the rest combined; all of them are in the table below.
Nameservers in use
as of 18 Sep 2026The hostnames actually found in the zones, with how many domains name each. The suffixes above are the rule; these are what the rule matched. Counted across all gTLDs rather than the current scope, since the aggregate is built in one pass over every zone. Showing the fifteen largest.
| Nameserver | Domains | Share of these |
|---|---|---|
| ns1045.ui-dns.biz | 97,294 | |
| ns1016.ui-dns.biz | 42,046 | |
| ns1017.ui-dns.biz | 41,195 | |
| ns1018.ui-dns.biz | 39,856 | |
| ns1019.ui-dns.biz | 39,827 | |
| ns1021.ui-dns.biz | 39,487 | |
| ns1020.ui-dns.biz | 37,630 | |
| ns1022.ui-dns.biz | 37,075 | |
| ns1023.ui-dns.biz | 36,585 | |
| ns1024.ui-dns.biz | 36,377 | |
| ns1025.ui-dns.biz | 36,185 | |
| ns1027.ui-dns.biz | 35,466 | |
| ns-de.1and1-dns.com | 34,862 | |
| ns1026.ui-dns.biz | 33,471 | |
| ns1028.ui-dns.biz | 33,424 |
These 15 nameservers carry 620,780 of the 4,882,343 domains this provider serves across every zone we parse, which spans new and legacy gTLDs together — more than the 4,232,905 counted under legacy gTLDs alone.
TLDs served
as of 18 Sep 2026| TLD | Domains here | Share of this provider | Of the TLD |
|---|---|---|---|
| .com | 3,220,817 | 1.93% | |
| .org | 390,613 | 3.22% | |
| .net | 285,892 | 2.31% | |
| .info | 284,053 | 5.47% | |
| .biz | 27,659 | 2.14% | |
| .name | 7,937 | 11.04% | |
| .pro | 7,584 | 0.66% | |
| .cat | 4,490 | 3.85% | |
| .mobi | 3,067 | 1.42% | |
| .asia | 643 | 0.09% | |
| .aero | 58 | 0.42% | |
| .travel | 42 | 0.15% | |
| .coop | 23 | 0.28% | |
| .tel | 10 | 0.03% | |
| .jobs | 8 | 0.07% | |
| .xxx | 6 | 0.02% | |
| .museum | 3 | 0.28% |
Data currency. Domain counts on this page are from zone files dated and refresh daily. Registrar figures are from ICANN's monthly registry reports for May 2026, which ICANN publishes about three months in arrears; zone files contain no registrar information, so no fresher source exists. Full detail on methodology and live pipeline status.