Is Hellenic Academic and Research Institutions CA or ZeroSSL more popular?

ZeroSSL is used by more websites in our catalog: 1,161 use Hellenic Academic and Research Institutions CA and 2,425 use ZeroSSL.

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

Hellenic Academic and Research Institutions CA sites have the higher median Ahrefs Domain Rating (Hellenic Academic and Research Institutions CA: 75, ZeroSSL: 23).

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

Between 2026-06 and 2026-07, Hellenic Academic and Research Institutions CA went from 0.17% to 0.13% of all tracked sites, while ZeroSSL went from 0.29% to 0.28%. ZeroSSL is gaining ground faster in our index.

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

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

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

Hellenic Academic and Research Institutions CA vs ZeroSSL

Q: Where does this Hellenic Academic and Research Institutions CA vs ZeroSSL 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	Hellenic Academic and Research Institutions CA	ZeroSSL
Websites	1,161	2,425
Market share	0.14%	0.29%
Share of top 10K sites	0.00%

Share of top 100K sites	0.06%	0.18%

Rank	#11	#9

Median DR	75	23

Average DR	74	28

Median keywords	658	1,066

Median referring domains	5,129	433

Median domain age	26 yrs	11 yrs

Average domain age	24 yrs	13 yrs

Average monthly traffic	13,566	66,319

Combined monthly traffic	15,749,601	160,824,401

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

Website	Language	DR (Ahrefs)	Total Keywords	Referring Domains	Domain Age	Traffic (Jun 2026)	Traffic Trend	Technology
mpg.de	German	89	61,365	103,616		560,707		Hellenic Academic and Research Institutions CA

dailymotion.com
LanguageEnglish
DR (Ahrefs)91
Total Keywords5,631,851
Referring Domains439,650
Domain Age21 yrs
Traffic (Jun 2026)29,762,292
Traffic Trend
TechnologyZeroSSL
petfinder.com
Language
DR (Ahrefs)86
Total Keywords309,140
Referring Domains35,407
Domain Age28 yrs
Traffic (Jun 2026)17,935,968
Traffic Trend
Technology
purina.com
Language
DR (Ahrefs)80
Total Keywords279,239
Referring Domains20,198
Domain Age30 yrs
Traffic (Jun 2026)15,738,940
Traffic Trend
TechnologyZeroSSL
easemate.ai
LanguageEnglish
DR (Ahrefs)50
Total Keywords31,731
Referring Domains2,281
Domain Age1 yr
Traffic (Jun 2026)12,535,413
Traffic Trend
Technology
chinahighlights.com
LanguageEnglish
DR (Ahrefs)78
Total Keywords76,271
Referring Domains25,545
Domain Age27 yrs
Traffic (Jun 2026)7,779,761
Traffic Trend
Technology
jellycat.com
LanguageEnglish
DR (Ahrefs)71
Total Keywords82,329
Referring Domains4,508
Domain Age26 yrs
Traffic (Jun 2026)4,163,338
Traffic Trend
Technology
sf.gov
LanguageEnglish
DR (Ahrefs)83
Total Keywords125,412
Referring Domains18,090
Domain Age10 yrs
Traffic (Jun 2026)3,627,926
Traffic Trend
TechnologyZeroSSL
screener.in
LanguageEnglish
DR (Ahrefs)72
Total Keywords59,916
Referring Domains4,356
Domain Age16 yrs
Traffic (Jun 2026)2,799,998
Traffic Trend
Technology
finedictionary.com
LanguageEnglish
DR (Ahrefs)40
Total Keywords282,639
Referring Domains2,583
Domain Age13 yrs
Traffic (Jun 2026)2,352,439
Traffic Trend
Technology
kwickmenu.com
LanguageEnglish
DR (Ahrefs)76
Total Keywords120,864
Referring Domains2,786
Domain Age9 yrs
Traffic (Jun 2026)1,927,802
Traffic Trend
Technology