Certificate authorities serving 1,495,086 domains

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

Let's Encrypt

887,591

59.4%

Google Trust Services

314,790

21.1%

other

101,730

6.8%

Sectigo

88,018

5.9%

Amazon

32,205

2.2%

GoDaddy / Starfield

21,407

1.4%

DigiCert

11,306

0.8%

GlobalSign

10,278

0.7%

GeoTrust

9,573

0.6%

ZeroSSL

8,069

0.5%

Certum

4,479

0.3%

Actalis

3,382

0.2%

Entrust

803

0.1%

Cloudflare

595

0.0%

Microsoft

447

0.0%

SSL.com

363

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).