Websites Using C1X — 2026 Data

A programmatic advertising platform providing header bidding demand and audience targeting solutions. Red Volcano tracks 35,342 publisher websites using C1X, with data refreshed weekly from proprietary crawlers.

● Data last updated: March 13, 2026
35,342
Publishers Using
United States
Top Country
News And Media
Top Vertical
21.6%
ads.txt Rate
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Top Publishers Using C1X

The highest-ranked websites using C1X, sorted by global traffic rank. Technology detection is based on Red Volcano's weekly crawl of ads.txt files, header bidding configurations, and JavaScript tag analysis.

#DomainGlobal RankMonthly PageviewsCountryCategory
1reddit.com#84,385,329,502United StatesComputers Electronics And Technology
2ebay.com#42666,753,176United StatesE-Commerce And Shopping
3craigslist.org#138113,939,213United StatesE-Commerce And Shopping
4uol.com.br#148248,121,697BrazilNews And Media
5indiatimes.com#167272,491,301IndiaNews And Media
6livedoor.jp#287159,743,578JapanNews And Media
7elpais.com#378134,491,945SpainNews And Media
8detik.com#431118,613,592IndonesiaNews And Media
9crazygames.com#47394,130,170United StatesGames
10nikkansports.com#54988,264,400JapanSports
11lokmat.com#56784,490,298IndiaNews And Media
12lemonde.fr#58884,525,310FranceNews And Media
13cbsnews.com#59698,151,638United StatesNews And Media
14reuters.com#63297,243,469United StatesNews And Media
15forbes.com#64695,239,788United StatesNews And Media
16o2.pl#65064,679,751PolandNews And Media
17skyscanner.net#75347,132,089United KingdomTravel And Tourism
18sky.it#76269,901,138ItalyArts And Entertainment
19marktplaats.nl#78239,815,018NetherlandsE-Commerce And Shopping
20markt.de#80436,447,128GermanyE-Commerce And Shopping
21sportbox.ru#81470,870,131RussiaSports
22abc.net.au#83366,377,380AustraliaNews And Media
23hochi.news#96762,127,026JapanSports
24x.ai#1,03148,441,520United StatesAi Chatbots And Tools
25clarin.com#1,04458,642,972ArgentinaNews And Media
26javtiful.com#1,06926,000,914IndonesiaAdult
27bihar.gov.in#1,08230,021,151IndiaLaw And Government
28jeuxvideo.com#1,17132,807,274FranceGames
29sponichi.co.jp#1,19045,613,993JapanNews And Media
30lastampa.it#1,27349,479,452ItalyNews And Media
31livejournal.com#1,31540,928,241RussiaComputers Electronics And Technology
32si.com#1,32649,819,940United StatesSports
33glassdoor.com#1,43830,247,032United StatesJobs And Career
34mlb.com#1,49839,408,029United StatesSports
35reclameaqui.com.br#1,51434,448,353BrazilBusiness And Consumer Services
36autotrader.co.za#1,57616,782,180South AfricaVehicles
37toyokeizai.net#1,59332,307,687JapanFinance
38haberturk.com#1,60631,221,113TurkeyNews And Media
39stockx.com#1,63330,086,474United StatesLifestyle
40fnac.com#1,63827,197,684FranceE-Commerce And Shopping
41elperiodico.com#1,67642,781,850SpainNews And Media
42francebleu.fr#1,77344,140,022FranceNews And Media
43kuruma-news.jp#1,80128,102,886JapanVehicles
44jutarnji.hr#1,88132,357,431Country 191News And Media
45ndmais.com.br#1,97536,299,507BrazilNews And Media
46abczdrowie.pl#1,97937,936,443PolandHealth
47president.jp#1,99326,336,606JapanNews And Media
48rtve.es#2,01331,590,436SpainArts And Entertainment
49krone.at#2,02527,458,615AustriaNews And Media
50vecteezy.com#2,07922,845,487IndiaArts And Entertainment

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C1X Adoption by Country

Geographic distribution of C1X adoption across publisher websites. Shows the top markets where publishers have integrated this technology.

United States
5,927 pubs
India
1,560 pubs
Russia
898 pubs
Brazil
747 pubs
Indonesia
709 pubs
United Kingdom
640 pubs
France
594 pubs
Canada
527 pubs
Germany
484 pubs
Spain
463 pubs
Australia
386 pubs
Italy
370 pubs
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C1X by Publisher Vertical

Which content categories show the highest adoption of C1X. Understanding vertical distribution helps SSPs and ad networks identify where this technology is most prevalent.

News And Media
2,109 pubs
Computers Electronics And Technology
689 pubs
Science And Education
599 pubs
Food And Drink
571 pubs
Arts And Entertainment
528 pubs
Games
520 pubs
Computers Electronics And Technology
490 pubs
Community And Society
447 pubs
Arts And Entertainment
432 pubs
Travel And Tourism
389 pubs
Arts And Entertainment
335 pubs
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SSP Partners of C1X Publishers

The most common SSP and monetization partnerships among publishers using C1X, based on ads.txt and sellers.json analysis.

Rubiconproject
1,175 pubs
Pubmatic
811 pubs
Smaato
302 pubs
Taboola
216 pubs
Freestar
183 pubs
Openx
175 pubs
Sharethrough
132 pubs
Infolinks
130 pubs
Sonobi
121 pubs
Gumgum
114 pubs

Get Full C1X Publisher Intelligence

Red Volcano provides complete data on all 35,342 publishers using C1X — with filters by country, vertical, traffic, and SSP relationships. Export lists, set up monitoring alerts, and access via API.

Frequently Asked Questions

According to Red Volcano's data, 35,342 publisher websites currently use C1X. This number is updated weekly based on our proprietary web crawlers that scan ads.txt files, JavaScript tags, and header bidding configurations across 32M+ websites.

The highest adoption of C1X is in United States, followed by other major digital advertising markets. Red Volcano tracks geographic distribution across 190+ countries, with detailed breakdowns available through our platform.

Publishers using C1X most commonly also use TheMediaGrid, Index Exchange, AJA, Integral Ad Science (IAS), vi. These co-occurring technologies indicate the typical header bidding and monetization stack of publishers in this segment.

The most common publisher vertical using C1X is News And Media. Red Volcano provides detailed category breakdowns showing adoption patterns across news, entertainment, sports, technology, and dozens of other verticals.

Red Volcano detects C1X through a combination of ads.txt analysis, JavaScript header bidding wrapper detection, sellers.json cross-referencing, and proprietary crawler technology. Our data is refreshed weekly to ensure accuracy.

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Related Data

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