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~/dnsniffer/issuers/zerossl·rank #7

▸ How many domains does ZeroSSL secure?

1,883,782

active domains whose current TLS certificate was issued by ZeroSSL, as of - 0.79% of all attributed domains.

# rank #7 of all CAs# all records held: 2,453,314# subdomains: 15# intermediates: 2# Austria
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~/issuers/zerossl/history·active domains
1,883,782
domains secured by ZeroSSL on 2026-10-15 · ▲ +1,385,955 (+278.40%) since 2025-06-30
324.6K772.0K1.22M1.67M2.11M2025-06-30: 497,827 active2025-07-31: 980,374 active2025-08-31: 990,973 active2025-09-30: 991,939 active2025-10-31: 991,939 active2025-11-30: 991,939 active2025-12-31: 1,262,184 active2026-01-31: 1,354,244 active2026-02-28: 1,354,244 active2026-03-31: 1,354,244 active2026-04-30: 1,707,166 active2026-05-31: 1,831,004 active2026-06-30: 1,893,280 active2026-07-31: 1,941,030 active2026-08-31: 1,940,759 active2026-09-01: 1,927,595 active2026-09-02: 1,904,817 active2026-09-03: 1,900,821 active2026-09-04: 1,898,211 active2026-09-05: 1,894,647 active2026-09-06: 1,892,915 active2026-09-07: 1,889,032 active2026-09-08: 1,887,228 active2026-09-09: 1,886,043 active2026-09-10: 1,883,655 active2026-09-11: 1,882,446 active2026-09-12: 1,875,059 active2026-09-13: 1,875,387 active2026-09-14: 1,875,708 active2026-09-15: 1,875,589 active2026-09-16: 1,872,768 active2026-09-17: 1,870,808 active2026-09-18: 1,868,724 active2026-09-19: 1,867,069 active2026-09-20: 1,865,359 active2026-09-21: 1,864,116 active2026-09-22: 1,862,944 active2026-09-23: 1,861,246 active2026-09-24: 1,914,673 active2026-09-25: 1,915,198 active2026-09-26: 1,917,048 active2026-09-27: 1,917,527 active2026-09-28: 1,913,239 active2026-09-29: 1,910,927 active2026-09-30: 1,909,849 active2026-10-01: 1,908,571 active2026-10-02: 1,906,789 active2026-10-03: 1,902,266 active2026-10-04: 1,900,725 active2026-10-05: 1,899,410 active2026-10-06: 1,897,499 active2026-10-07: 1,893,401 active2026-10-08: 1,891,030 active2026-10-09: 1,889,066 active2026-10-10: 1,885,446 active2026-10-11: 1,885,029 active2026-10-12: 1,884,615 active2026-10-13: 1,885,541 active2026-10-14: 1,884,886 active2026-10-15: 1,883,782 active2025-06-302026-10-15

# y-axis starts at 324.6K, 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
▲ +0.44%
+8,193 domains
90 days
▼ -0.50%
-9,498 domains
1 year
▲ +89.91%
+891,843 domains
# intermediate CAs
Intermediate certificate authorities operating under ZeroSSL, with the number of active domains each currently secures.
intermediatecountrydomains
ZeroSSL RSA DV SSL CA 2Austria1,478,462
ZeroSSL RSA Domain Secure Site CA-405,320
# faq
? How many domains does ZeroSSL secure?
ZeroSSL is the certificate authority for 1,883,782 active domains as of October 15, 2026 - 0.79% of every domain DNSniffer can attribute to an issuer.
? Is ZeroSSL gaining or losing market share?
The number of domains secured by ZeroSSL has grown by 89.91% over the last year (+891,843 domains).
? Which intermediate CAs does ZeroSSL sign from?
We have seen 2 intermediates under ZeroSSL, the busiest being “ZeroSSL RSA DV SSL CA 2” with 1,478,462 domains. The full list, with per-intermediate counts, is on this page.
? Where does this number come from?
DNSniffer ingests Certificate Transparency logs continuously and records the issuer of the most recent certificate seen for each domain, then snapshots the per-issuer count once a day. It measures how much of the live web a CA currently secures, not how many certificates it has issued over its lifetime.
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