Consent, security and monitoring
Websites using IAB TCF consent API (__tcfapi)
The IAB Transparency and Consent Framework API is the standard interface consent platforms expose to advertising vendors. About 100,097 websites in the PageSourceSearch index contain the code that reveals it; the 50 highest-ranked are listed below.
How is IAB TCF consent API (__tcfapi) detected?
TCF-compliant consent stubs define the __tcfapi function inline in the page so vendors can queue consent requests. The discovery keyword is the exact bytes PageSourceSearch looks for in every stored page and script:
__tcfapi Search the index for it
A literal is matched byte for byte, case-sensitively. Combine it with another keyword, a domain, a kind or a date filter on the search page to narrow the list. About IAB TCF consent API (__tcfapi)
Top 50 websites using IAB TCF consent API (__tcfapi)
Ranked by the domain's position in the crawl's ranked list (Common Crawl harmonic centrality), highest first. view source opens the stored page or script with the match highlighted. Computed 2026-10-04 12:09:01 UTC.
How it appears in the source
From theguardian.com (js):
A],t[n.REMOVE_EVENT_LISTENER]=t[n.GET_TC_DATA]),this.customCommands=t}try{this.callQueue=window.__tcfapi()||[]}catch(e){this.callQueue=[]}finally{window.__tcfapi=this.apiCall.bind(this),this.purgeQueu
Questions about finding IAB TCF consent API (__tcfapi)
- How does PageSourceSearch know a website uses IAB TCF consent API (__tcfapi)?
- By the source itself: TCF-compliant consent stubs define the __tcfapi function inline in the page so vendors can queue consent requests. PageSourceSearch stores the raw HTML and first-party JavaScript of each crawled site and matches the keyword byte for byte, so every listed site's stored source contains it.
- Is this a complete list of websites using IAB TCF consent API (__tcfapi)?
- No. The page lists the 50 highest-ranked sites in the index whose source holds the keyword, out of about 100,097 websites that do; the count is the index's estimate at the time the list was computed. Run the keyword as a search to page through all of them, or add a kind or date filter.
- How do I find websites that use IAB TCF consent API (__tcfapi) together with another technology?
- Search for both keywords at once: several terms separated by spaces must all be found on the same site, or with the Same page toggle in the same page. For example __tcfapi with wp-content/plugins/ lists the WordPress sites that use IAB TCF consent API (__tcfapi).