Does Certum or Hellenic Academic and Research Institutions CA have higher-authority sites?

Hellenic Academic and Research Institutions CA sites have the higher median Ahrefs Domain Rating (Certum: 55, Hellenic Academic and Research Institutions CA: 75).

Is Certum or Hellenic Academic and Research Institutions CA growing faster?

Between 2026-06 and 2026-07, Certum went from 0.08% to 0.07% of all tracked sites, while Hellenic Academic and Research Institutions CA went from 0.17% to 0.13%. Certum is gaining ground faster in our index.

Can a site use both Certum and Hellenic Academic and Research Institutions CA?

No. A site runs a single SSL certificate authority, so Certum and Hellenic Academic and Research Institutions CA are mutually exclusive.

Certum vs Hellenic Academic and Research Institutions CA — Site Stats Database

Certum vs Hellenic Academic and Research Institutions CA

Q: Is Certum or Hellenic Academic and Research Institutions CA more popular?

Hellenic Academic and Research Institutions CA is used by more websites in our catalog: 579 use Certum and 1,161 use Hellenic Academic and Research Institutions CA.

Q: Where does this Certum vs Hellenic Academic and Research Institutions CA data come from?

Adoption is counted from Site Stats Database's own crawl; Domain Rating comes from Ahrefs and traffic from DataForSEO. Figures reflect the sites we track and refresh at least monthly.

A side-by-side comparison of two ssl certificate authorities, based on the 842,065 SSL Authority sites tracked by Site Stats Database.

Last updated July 1, 2026

Metric	Certum	Hellenic Academic and Research Institutions CA
Websites	579	1,161
Market share	0.07%	0.14%
Share of top 10K sites	0.00%

Share of top 100K sites	0.03%	0.06%

Rank	#17	#11

Median DR	55	75

Average DR	52	74

Median keywords	396	658

Median referring domains	1,388	5,129

Median domain age	15 yrs	26 yrs

Average domain age	15 yrs	24 yrs

Average monthly traffic	15,804	13,566

Combined monthly traffic	9,150,719	15,749,601

auschwitz.org
LanguagePolish
DR (Ahrefs)76
Total Keywords9,509
Referring Domains11,787
Domain Age25 yrs
Traffic (Jun 2026)703,253
Traffic Trend
TechnologyCertum
simcosplay.com
LanguageEnglish
DR (Ahrefs)21
Total Keywords20,259
Referring Domains1,668
Domain Age7 yrs
Traffic (Jun 2026)683,447
Traffic Trend
Technology
uhomes.com
LanguageEnglish
DR (Ahrefs)55
Total Keywords119,316
Referring Domains2,552
Domain Age23 yrs
Traffic (Jun 2026)570,251
Traffic Trend
Technology
abadis.ir
LanguagePersian
DR (Ahrefs)70
Total Keywords110,449
Referring Domains6,192
Domain Age
Traffic (Jun 2026)490,697
Traffic Trend
TechnologyCertum
floorplancreator.net
LanguageEnglish
DR (Ahrefs)42
Total Keywords4,628
Referring Domains987
Domain Age13 yrs
Traffic (Jun 2026)460,176
Traffic Trend
Technology
anchenggy.com
LanguageEnglish
DR (Ahrefs)27
Total Keywords6,466
Referring Domains619
Domain Age12 yrs
Traffic (Jun 2026)332,303
Traffic Trend
Technology
igmetall.de
LanguageGerman
DR (Ahrefs)75
Total Keywords306
Referring Domains9,381
Domain Age
Traffic (Jun 2026)310,727
Traffic Trend
TechnologyCertum
mywanderlust.pl
LanguageEnglish
DR (Ahrefs)47
Total Keywords9,706
Referring Domains2,952
Domain Age13 yrs
Traffic (Jun 2026)283,835
Traffic Trend
Technology
scirp.org
LanguageEnglish
DR (Ahrefs)86
Total Keywords90,804
Referring Domains62,358
Domain Age18 yrs
Traffic (Jun 2026)272,944
Traffic Trend
TechnologyCertum
mfa.gov.ir
Language
DR (Ahrefs)72
Total Keywords3,297
Referring Domains5,427
Domain Age
Traffic (Jun 2026)267,826
Traffic Trend
TechnologyCertum

Website	Language	DR (Ahrefs)	Total Keywords	Referring Domains	Domain Age	Traffic (Jun 2026)	Traffic Trend	Technology
auschwitz.org	Polish	76	9,509	11,787	25 yrs	703,253		Certum

mpg.de
LanguageGerman
DR (Ahrefs)89
Total Keywords61,365
Referring Domains103,616
Domain Age
Traffic (Jun 2026)560,707
Traffic Trend
TechnologyHellenic Academic and Research Institutions CA
ucm.es
LanguageSpanish
DR (Ahrefs)84
Total Keywords21,955
Referring Domains58,616
Domain Age
Traffic (Jun 2026)520,587
Traffic Trend
TechnologyHellenic Academic and Research Institutions CA
eso.org
LanguageEnglish
DR (Ahrefs)82
Total Keywords18,717
Referring Domains32,647
Domain Age35 yrs
Traffic (Jun 2026)398,404
Traffic Trend
TechnologyHellenic Academic and Research Institutions CA
cun.es
LanguageSpanish
DR (Ahrefs)75
Total Keywords72,981
Referring Domains9,254
Domain Age
Traffic (Jun 2026)394,191
Traffic Trend
TechnologyHellenic Academic and Research Institutions CA
hal.science
LanguageEnglish
DR (Ahrefs)85
Total Keywords68,893
Referring Domains58,817
Domain Age
Traffic (Jun 2026)357,126
Traffic Trend
Technology
belgium.be
LanguageEnglish
DR (Ahrefs)90
Total Keywords12,117
Referring Domains64,675
Domain Age31 yrs
Traffic (Jun 2026)290,046
Traffic Trend
Technology
astro4edu.org
LanguageEnglish
DR (Ahrefs)48
Total Keywords15,128
Referring Domains1,030
Domain Age6 yrs
Traffic (Jun 2026)262,741
Traffic Trend
Technology
plantnet.org
LanguageEnglish
DR (Ahrefs)74
Total Keywords11,086
Referring Domains7,165
Domain Age12 yrs
Traffic (Jun 2026)234,714
Traffic Trend
Technology
bund.de
LanguageEnglish
DR (Ahrefs)94
Total Keywords99,279
Referring Domains462,466
Domain Age
Traffic (Jun 2026)224,202
Traffic Trend
TechnologyHellenic Academic and Research Institutions CA
habsburger.net
LanguageGerman
DR (Ahrefs)63
Total Keywords6,739
Referring Domains3,814
Domain Age17 yrs
Traffic (Jun 2026)188,745
Traffic Trend
Technology