Websites using ES Module Shims

About ES Module Shims

ES Module Shims is a polyfill for import maps and other ES module features in browsers. It enables using modern module features in browsers that don't natively support them.

Identifying ES Module Shims in a website's stack reveals key decisions about its architecture, performance strategy, and development approach. Web Reveal automatically detects ES Module Shims and hundreds of other technologies by analyzing page source, HTTP headers, and JavaScript signatures—giving you instant insight into how any site is built.

Why do websites use ES Module Shims?

Teams choose ES Module Shims because it fits neatly into modern workflows and solves real-world problems around performance, reliability, or developer productivity. Understanding which sites rely on it—and how widely it has been adopted—helps developers, marketers, and researchers make informed decisions when evaluating their own technology choices.

How does Web Reveal detect ES Module Shims?

Web Reveal identifies ES Module Shims by inspecting a combination of signals: JavaScript global variables and library fingerprints loaded in the page, distinctive patterns in HTML markup and meta tags, HTTP response headers such as X-Powered-By and Server, asset file paths and CDN URLs, and cookie names set by the technology. This multi-signal approach minimizes false positives and ensures accurate results even when sites obscure their stack.

What can I learn from knowing a site uses ES Module Shims?

Knowing that a competitor or industry leader uses ES Module Shims can inform your own architectural or vendor decisions. It also helps security researchers understand the attack surface of a given site, lets recruiters gauge a company's technical depth, and gives product teams data-driven insight into adoption trends across the web.

Frequently asked questions about ES Module Shims

What is ES Module Shims?

ES Module Shims is a polyfill for import maps and other ES module features in browsers. It enables using modern module features in browsers that don't natively support them.

How can I check if a website uses ES Module Shims?

Enter the website's URL into the Web Reveal scanner. It will instantly analyse the page and report whether ES Module Shims is detected, along with every other technology in the site's stack.

Is ES Module Shims widely used?

Web Reveal has already detected ES Module Shims on a growing number of websites across different industries. Use the scanner to explore real examples and see how broadly it has been adopted.

What other technologies are commonly used alongside ES Module Shims?

Scanning sites that use ES Module Shims often reveals complementary technologies in the same stack—such as CDNs, analytics platforms, CMS solutions, and JavaScript frameworks. Run a scan on any of the sites listed above to see the full technology breakdown.