Using ES Modules in the Browser Today

Using ES modules in browsers: Current status and future

Core points:

• ES6 (ES2015) introduced the JavaScript native module standard, but initially poor browser support led developers to use module loaders to bundle dependencies into a single ES5-compatible browser file.
• Mainstream browsers such as Safari, Chrome, Firefox, and Edge now support the import syntax of the ES6 module, enabling a more efficient and standardized code structure.
• While the ES6 module's support continues to improve, build tools such as Babel and Webpack are still indispensable as browsers continue to be optimized. Combining HTTP2's multi-resource streaming capabilities and browser preloading capabilities, the ES module is expected to bring significant performance improvements.
• While now you can use the ES module directly in modern browsers without the need for a translator or bundler, it is still recommended to create separate packages for older browsers. More and more libraries are starting to be released as ES modules, but they are still primarily targeted at bundlers rather than direct imports.

This article will demonstrate how to use the ES module in today's browser.

Before recently, JavaScript did not have the concept of modules. It is impossible to directly reference or include a JavaScript file into another file. As application size and complexity grow, this makes writing JavaScript for browsers tricky.

A common solution is to use

// html.js
export function tag (tag, text) {
  const el = document.createElement(tag)
  el.textContent = text

  return el
}</pre>
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<🎜></pre>
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// app.js
import { tag } from './html.js'

const h1 = tag('h1', '? Hello Modules!')
document.body.appendChild(h1)</pre>
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type="module"Simply add </pre> <p> <strong> to your

importRequirementsfile://npx serve

for extraction, as it does not work with

to start a server in the current directory for local testing. browser-es-module-loader

If you are bold enough to try this in production now, you still need to create separate packages for older browsers. A polyfill is provided in which follows the specification. However, this is not recommended for production environments at all.

Don't discard build tools like Babel and Webpack immediately, because browsers are still implementing methods for optimizing extraction. Nevertheless, there are still performance pitfalls and advantages in future use of ES modules.