Websites Powered by mod_jk
12,360 websites tracked using mod_jk (Web server extensions) · tomcat.apache.org
mod_jk is a web-server extension or module. Its official site is tomcat.apache.org. PoweredBy tracks the websites that use mod_jk across the public web; the tracked counts, adoption trend, and site list on this page are updated from our ongoing crawl of the web server extensions ecosystem.
Usage trend
2K
4K
6K
Apr 2018
May 2020
Jul 2022
Aug 2024
Sep 2026
Domains observed using mod_jk in each month's HTTP Archive crawl,
Apr 2018 to Sep 2026 · peak 5,932 in Aug 2022. The tracked total above also
counts sites not re-crawled recently.
Core Web Vitals
LCP 1.3 s
INP 50 ms
CLS 0
TTFB 500 ms
Median site among 5,473 mod_jk sites with Chrome UX data, p75 values, Sep 2026.
Top countries
South Korea
2,059
United States
1,618
Italy
1,027
India
936
Spain
768
Germany
724
Japan
711
Canada
707
Sites using mod_jk by audience country, Chrome UX Report.
Usage by industry
| Industry | Share | Websites |
|---|---|---|
| Government | 0.06% | 5 |
| Education | 0.06% | 29 |
| Arts and entertainment | 0.02% | 9 |
| Finance and insurance | 0.02% | 3 |
| Retail | 0.01% | 39 |
| Travel and hospitality | 0.01% | 9 |
| Healthcare | <0.01% | 9 |
| Professional services | <0.01% | 3 |
| Software and apps | <0.01% | 8 |
| News and media | <0.01% | 2 |
| Beauty and wellness | <0.01% | 1 |
| Automotive | <0.01% | 1 |
Share of each industry's websites with a detected stack that use mod_jk; industries come from what sites declare in their own structured data.
Top sites by authority
9+
3% · 10 of 372 sites
8+
<1% · 72 of 7,677 sites
7+
<1% · 152 of 45,712 sites
6+
<1% · 248 of 110,136 sites
5+
<1% · 330 of 246,751 sites
The share of the web's most authoritative domains, by Open Page Rank tier, seen running mod_jk in recent crawls. Only 372 domains worldwide score 9 or higher.
Websites using mod_jk
| # | Domain | Open Page RankOPR | Est. monthly visits (US)Visits (US) | Keywords | First seen |
|---|---|---|---|---|---|
| 1 | harvard.edu | 9.24/10 | 472,700 | 11,444 | Aug 2018 |
| 2 | ca.gov | 9.23/10 | 1,455,600 | 26,086 | Aug 2018 |
| 3 | stanford.edu | 9.19/10 | 3,302,700 | 5,160 | Oct 2018 |
| 4 | mit.edu | 9.18/10 | 163,800 | 31,239 | Aug 2018 |
| 5 | wiley.com | 9.14/10 | 76,400 | 29,151 | Apr 2019 |
| 6 | usda.gov | 9.14/10 | 474,600 | 136,928 | Aug 2018 |
| 7 | epa.gov | 9.13/10 | 3,829,800 | 580,699 | Aug 2018 |
| 8 | cambridge.org | 9.04/10 | 633,100 | 518,312 | Aug 2018 |
| 9 | psu.edu | 9.01/10 | 580,400 | 80,390 | Aug 2018 |
| 10 | uk.com | 9.00/10 | 2 | 12 | Jan 2016 |
| 11 | fao.org | 8.93/10 | 213,900 | 125,762 | May 2019 |
| 12 | northwestern.edu | 8.86/10 | 193,400 | 45,922 | Jan 2021 |
| 13 | ufl.edu | 8.84/10 | 241,500 | 3,277 | Sep 2018 |
| 14 | ucsd.edu | 8.84/10 | 48,100 | 2,261 | Mar 2025 |
| 15 | nrw.de | 8.83/10 | - | - | Jan 2019 |
| 16 | illinois.edu | 8.83/10 | 47,000 | 3,612 | May 2017 |
| 17 | ucdavis.edu | 8.83/10 | 381,100 | 81,485 | Aug 2018 |
| 18 | tokyo.lg.jp | 8.83/10 | - | - | Jul 2024 |
| 19 | pa.gov | 8.78/10 | 3,807,400 | 1,087,569 | Feb 2020 |
| 20 | uci.edu | 8.76/10 | 94,600 | 9,503 | Aug 2018 |
| 21 | nielsen.com | 8.75/10 | 89,300 | 35,566 | Aug 2018 |
| 22 | rutgers.edu | 8.75/10 | 146,600 | 28,567 | Aug 2018 |
| 23 | faa.gov | 8.73/10 | 2,209,300 | 278,808 | Apr 2019 |
| 24 | unibo.it | 8.68/10 | 11,100 | 4,872 | Aug 2018 |
| 25 | esa.int | 8.67/10 | 412,100 | 94,679 | Mar 2020 |
| 26 | caltech.edu | 8.65/10 | 148,200 | 20,173 | Aug 2018 |
| 27 | gencat.cat | 8.63/10 | 86 | 174 | Aug 2018 |
| 28 | colostate.edu | 8.62/10 | 189,100 | 10,871 | Mar 2025 |
| 29 | uic.edu | 8.61/10 | 68,900 | 11,201 | Oct 2021 |
| 30 | ri.gov | 8.59/10 | 305,500 | 10,044 | Aug 2022 |
| 31 | usf.edu | 8.57/10 | 459,500 | 80,745 | Aug 2018 |
| 32 | emory.edu | 8.56/10 | 202,500 | 15,781 | Aug 2022 |
| 33 | juntadeandalucia.es | 8.54/10 | 5,400 | 17,242 | Jan 2019 |
| 34 | state.pa.us | 8.50/10 | - | - | Jul 2020 |
| 35 | uni-goettingen.de | 8.49/10 | 6,400 | 3,874 | Aug 2018 |
| 36 | uni-koeln.de | 8.49/10 | 1,200 | 427 | May 2019 |
| 37 | uni-muenster.de | 8.43/10 | 9,000 | 4,657 | Aug 2018 |
| 38 | unh.edu | 8.42/10 | 157,800 | 35,868 | Nov 2024 |
| 39 | beniculturali.it | 8.41/10 | - | - | Aug 2018 |
| 40 | inserm.fr | 8.40/10 | 3,100 | 2,265 | Aug 2018 |
| 41 | upv.es | 8.38/10 | 2,500 | 2,576 | Aug 2018 |
| 42 | ugr.es | 8.38/10 | 8,500 | 8,711 | Aug 2018 |
| 43 | lodz.pl | 8.37/10 | 90 | 193 | Jan 2022 |
| 44 | dyndns.org | 8.36/10 | - | - | Aug 2022 |
| 45 | qmul.ac.uk | 8.36/10 | 35,400 | 21,676 | Aug 2018 |
| 46 | interno.gov.it | 8.36/10 | 1,100 | 1,313 | Feb 2019 |
| 47 | unimi.it | 8.35/10 | 3,300 | 3,182 | Aug 2018 |
| 48 | austintexas.gov | 8.33/10 | 949,600 | 181,969 | Dec 2020 |
| 49 | unipi.it | 8.32/10 | 1,500 | 1,950 | Aug 2018 |
| 50 | udc.es | 8.29/10 | 280 | 628 | Jul 2025 |
| 51 | nm.gov | 8.29/10 | 34,700 | 4,741 | May 2026 |
| 52 | universityofcalifornia.edu | 8.28/10 | 204,100 | 53,408 | May 2019 |
| 53 | unistra.fr | 8.26/10 | 1,500 | 1,386 | Dec 2025 |
| 54 | vector.co.jp | 8.25/10 | 110 | 403 | Aug 2018 |
| 55 | unito.it | 8.25/10 | 630 | 627 | Aug 2018 |
| 56 | usal.es | 8.22/10 | 3,200 | 1,130 | Aug 2018 |
| 57 | uma.es | 8.15/10 | 1,700 | 2,592 | Aug 2018 |
| 58 | geonames.org | 8.12/10 | 291,800 | 35,597 | Jan 2017 |
| 59 | univ-lyon1.fr | 8.12/10 | 930 | 492 | Aug 2022 |
| 60 | joins.com | 8.11/10 | 17 | 6 | Aug 2022 |
| 61 | unina.it | 8.10/10 | 2,800 | 1,842 | Aug 2018 |
| 62 | snu.ac.kr | 8.09/10 | 69 | 64 | Aug 2018 |
| 63 | flinders.edu.au | 8.07/10 | 7,800 | 4,781 | Mar 2024 |
| 64 | unive.it | 8.06/10 | 3,800 | 1,946 | Aug 2018 |
| 65 | camcom.it | 8.05/10 | - | - | Aug 2018 |
| 66 | seoul.go.kr | 8.04/10 | 42 | 19 | Feb 2019 |
| 67 | juniper.net | 8.02/10 | 161,900 | 25,963 | Oct 2018 |
| 68 | uc.cl | 8.02/10 | 2,800 | 2,417 | Aug 2018 |
| 69 | uliege.be | 8.01/10 | 320 | 106 | Jan 2019 |
| 70 | uva.es | 8.01/10 | 240 | 324 | Oct 2022 |
| 71 | myswitzerland.com | 8.00/10 | 378,600 | 30,847 | Aug 2018 |
| 72 | u-strasbg.fr | 8.00/10 | - | - | Aug 2018 |
| 73 | njit.edu | 7.99/10 | 46,600 | 14,194 | Apr 2022 |
| 74 | chula.ac.th | 7.99/10 | 5,600 | 2,737 | Aug 2022 |
| 75 | uillinois.edu | 7.99/10 | 28,200 | 2,935 | Aug 2018 |
| 76 | orst.edu | 7.99/10 | - | - | May 2017 |
| 77 | tiscali.it | 7.97/10 | 340 | 126 | Aug 2018 |
| 78 | kerala.gov.in | 7.94/10 | 540 | 50 | Jan 2021 |
| 79 | pref.okayama.jp | 7.94/10 | 78 | 26 | Apr 2024 |
| 80 | ucmerced.edu | 7.92/10 | 64,900 | 8,155 | Mar 2025 |
| 81 | juntaex.es | 7.87/10 | 330 | 943 | Feb 2024 |
| 82 | unal.edu.co | 7.85/10 | 1,200 | 240 | Aug 2018 |
| 83 | carm.es | 7.84/10 | 3,800 | 3,901 | Oct 2023 |
| 84 | lmu.edu | 7.84/10 | 152,300 | 12,398 | Dec 2018 |
| 85 | uerj.br | 7.83/10 | 330 | 207 | Sep 2022 |
| 86 | vutbr.cz | 7.82/10 | 4 | 1 | Jul 2019 |
| 87 | unisi.it | 7.81/10 | 920 | 422 | Aug 2018 |
| 88 | uca.es | 7.79/10 | 580 | 632 | Aug 2018 |
| 89 | ufpe.br | 7.78/10 | 42,700 | 34,698 | Apr 2019 |
| 90 | uem.br | 7.76/10 | 21 | 19 | Jul 2026 |
| 91 | nets.eu | 7.75/10 | 220 | 319 | Dec 2021 |
| 92 | u-szeged.hu | 7.74/10 | 880 | 213 | Aug 2018 |
| 93 | regione.fvg.it | 7.71/10 | 490 | 1,254 | May 2024 |
| 94 | regione.campania.it | 7.71/10 | 180 | 516 | Aug 2018 |
| 95 | fernuni-hagen.de | 7.71/10 | 500 | 515 | May 2021 |
| 96 | bihar.gov.in | 7.69/10 | - | - | Oct 2023 |
| 97 | dmu.ac.uk | 7.67/10 | 9,000 | 5,185 | Jan 2025 |
| 98 | gettysburg.edu | 7.67/10 | 25,900 | 9,024 | Apr 2020 |
| 99 | senac.br | 7.66/10 | 21 | 49 | Aug 2022 |
| 100 | inaf.it | 7.65/10 | 160 | 120 | Jul 2022 |
Open Page Rank is the domain's authority score (0 to 10, from the open web link graph); the list is ordered by it and covers sites seen in recent crawls. Visits and keywords are estimated US organic search figures.
Download top 10,000 as CSV (zip) →
Columns: domain, Open Page Rank, first seen, last seen, industry (from the site's own structured data, blank when none).