babel-polyfill vs core-js: What are the differences?

Introduction

In modern web development, transpiling and polyfilling are common techniques used to ensure that code written in newer versions of JavaScript can run on older browsers. Two popular tools for achieving this are babel-polyfill and core-js. Both tools provide the necessary polyfills, but there are some key differences between them.

1. Browser support: Babel-polyfill provides a wider range of browser support out of the box compared to core-js. With babel-polyfill, you can expect to support older browsers such as Internet Explorer 9 and above. On the other hand, core-js requires additional configuration and customization to achieve the same level of browser support.

2. Bundle size: Core-js allows for more granular control over the specific polyfills needed for your project. This means that you can import only the polyfills that are necessary for your target browsers, resulting in a smaller bundle size. Babel-polyfill, on the other hand, includes a larger set of polyfills by default, which can lead to a larger bundle size if not optimized.

3. Integration with build tools: Babel-polyfill integrates seamlessly with Babel and is often used alongside it. This means that you can use Babel to transpile your JavaScript code and babel-polyfill to provide the necessary polyfills. Core-js, on the other hand, is more versatile and can be used with various build tools like webpack, Rollup, or directly imported into your project.

4. Customization options: Core-js provides more customization options compared to babel-polyfill. With core-js, you can configure which specific features and polyfills to include based on your project's needs. This allows for a more optimized and tailored polyfilling solution. Babel-polyfill, on the other hand, includes a predefined set of polyfills and does not offer as much flexibility in terms of customization.

5. Maintenance and updates: Both babel-polyfill and core-js are actively maintained and regularly updated to keep up with the latest standards and browser support. However, since babel-polyfill is tightly integrated with Babel, it often receives updates in sync with Babel updates. This can be advantageous if you are already using Babel in your project.

6. Community and ecosystem: Both babel-polyfill and core-js have a large and active community of users. However, babel-polyfill, being closely associated with Babel, has a larger user base and a more established ecosystem. This means that you may find more resources, tutorials, and support for babel-polyfill compared to core-js.

In summary, babel-polyfill provides wider browser support out of the box and is tightly integrated with Babel. Core-js, on the other hand, offers more flexibility in terms of customization, allowing for a smaller bundle size and tailored polyfilling solution. Choose the tool that best fits your project's requirements and compatibility needs.