~/dnsniffer/issuers/certainly·rank #16
▸ How many domains does Certainly secure?
61,270
active domains whose current TLS certificate was issued by Certainly, as of - 0.03% of all attributed domains.
# rank #16 of all CAs ▼ 1 in 30d# all records held: 63,672# subdomains: 0# intermediates: 1
~/issuers/certainly/history·active domains
61,270
domains secured by Certainly on 2026-10-15 · ▲ +31,913 (+108.71%) since 2025-06-30
# y-axis starts at 25.5K, 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
▲ +2.61%
+1,556 domains
90 days
▲ +9.79%
+5,465 domains
1 year
▲ +48.98%
+20,144 domains
# intermediate CAs
| intermediate | country | domains |
|---|---|---|
| Certainly Intermediate R1 | - | 61,270 |
# faq
- ? How many domains does Certainly secure?
- Certainly is the certificate authority for 61,270 active domains as of October 15, 2026 - 0.03% of every domain DNSniffer can attribute to an issuer.
- ? Is Certainly gaining or losing market share?
- The number of domains secured by Certainly has grown by 48.98% over the last year (+20,144 domains).
- ? Which intermediate CAs does Certainly sign from?
- We have seen 1 intermediates under Certainly, the busiest being “Certainly Intermediate R1” with 61,270 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.