Certificate authorities serving 2,798,980 domains

Who signs the TLS certificate currently presented by each site. One row per domain — its most recent still-valid certificate.

Let's Encrypt

1,036,000

37.0%

other

852,321

30.5%

Google Trust Services

559,059

20.0%

Sectigo

164,203

5.9%

Amazon

46,102

1.6%

GoDaddy / Starfield

42,543

1.5%

ZeroSSL

19,821

0.7%

Actalis

17,178

0.6%

DigiCert

16,464

0.6%

GeoTrust

15,409

0.6%

GlobalSign

15,307

0.5%

Certum

10,711

0.4%

Cloudflare

1,140

0.0%

Entrust

1,099

0.0%

Microsoft

975

0.0%

SSL.com

593

0.0%

Buypass

0.0%

Method

We seed certificate history from public Certificate Transparency logs on the first crawl and keep observing as new entries appear. For this page we filter to certificates with not_after > now() and pick the latest one per domain. Issuer strings are normalised (R13, E7, and "Let's Encrypt Authority X3" all collapse to Let's Encrypt).