Websites using mailcheck (npm)
mailcheck is an npm package; the sites listed here load it from the jsDelivr CDN, where it is among the most requested packages. About 4,412 websites in the PageSourceSearch index contain the code that reveals it; the 12 highest-ranked are listed below.
How is mailcheck (npm) detected?
A page loading mailcheck from jsDelivr references cdn.jsdelivr.net/npm/mailcheck followed by a version or a path. The discovery keyword is the exact bytes PageSourceSearch looks for in every stored page and script:
cdn\.jsdelivr\.net/npm/mailcheck[@/] regex 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 mailcheck (npm)
Top 50 websites using mailcheck (npm)
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 2026-10-12 18:18:13 UTC; the list stopped short of 50 because the search's budget ran out.
How it appears in the source
From marchforourlives.org (html):
<script id="mailcheck_js-js" src="https://cdn.jsdelivr.net/npm/[email protected]/src/mailcheck.min.js?ver=1.1.1"></script>
See every site: search for cdn\.jsdelivr\.net/npm/mailcheck[@/]
Questions about finding mailcheck (npm)
- How does PageSourceSearch know a website uses mailcheck (npm)?
- By the source itself: A page loading mailcheck from jsDelivr references cdn.jsdelivr.net/npm/mailcheck followed by a version or a path. 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 mailcheck (npm)?
- No. The page lists the 50 highest-ranked sites in the index whose source holds the keyword, out of about 4,412 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 mailcheck (npm) 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 cdn\.jsdelivr\.net/npm/mailcheck[@/] with wp-content/plugins/ lists the WordPress sites that use mailcheck (npm).