ES Module Shims polyfills import maps and other module features.
About 75,771 websites in the PageSourceSearch index contain the code that reveals it; the 50 highest-ranked are listed below.
How is ES Module Shims detected?
The page loads es-module-shims.js before its import map. The discovery keyword is the exact bytes PageSourceSearch looks for in every stored page and script:
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 ES Module Shims
Top 50 websites using ES Module Shims
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 15:47:25 UTC.
How does PageSourceSearch know a website uses ES Module Shims?
By the source itself: The page loads es-module-shims.js before its import map. 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 ES Module Shims?
No. The page lists the 50 highest-ranked sites in the index whose source holds the keyword, out of about 75,771 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 ES Module Shims 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 es-module-shims with wp-content/plugins/ lists the WordPress sites that use ES Module Shims.