使用axios而非ES6 fetch的理由？引入babel-polyfill后是否无需axios？

Great question—let's unpack this because while babel-polyfill does solve fetch's browser compatibility gap, there's still plenty of value in sticking with Axios for most projects.

First, let's clarify what babel-polyfill actually does for fetch: it adds a polyfill for the native ES6 fetch API, allowing it to work in older browsers that don't support it natively (like IE11). But that's where its role ends. Axios brings a ton of built-in features that you'd have to manually implement with fetch, even with a polyfill.

Here are key reasons you might still prefer Axios:

• Built-in request/response interceptors: Need to add auth tokens to every request? Log all responses? Handle global error messages? Axios has dedicated interceptors that let you do this in a clean, centralized way—no need to wrap every fetch call with custom code.
• Automatic JSON handling: Axios automatically parses JSON responses into JavaScript objects. With fetch, you have to explicitly call .json() on the response, and you'll run into errors if the response isn't valid JSON (requiring extra error checking every time).
• Simpler error handling: Fetch only rejects promises on network errors (like no internet connection). HTTP errors (404, 500, etc.) still resolve successfully, forcing you to manually check response.ok in every request. Axios, by contrast, rejects promises for any HTTP status code outside the 2xx range, making error handling more consistent and less repetitive.
• Easy request cancellation: Axios has had built-in support for canceling requests for years (originally via CancelToken, now aligned with the standard AbortController too). While fetch also supports AbortController now, Axios's API for cancellation is often more intuitive, especially when managing multiple concurrent requests.
• Built-in timeout support: Setting a timeout for a request is as simple as adding a timeout property to your Axios config. With fetch, you have to manually implement timeout logic using Promise.race() with a delayed reject—extra boilerplate every time.
• Cross-environment consistency: Axios works seamlessly in both browsers and Node.js (it uses the browser's XMLHttpRequest under the hood, and Node's http module on the server). Fetch, on the other hand, requires a polyfill (like node-fetch) for older Node.js versions, and even with newer Node versions, its behavior can have subtle differences from the browser implementation.
• Progress tracking: Axios makes it easy to monitor upload and download progress with onUploadProgress and onDownloadProgress callbacks. Tracking progress with fetch requires working directly with ReadableStream, which is far more low-level and tedious.

Wrap-Up #

If you're only making simple, one-off HTTP requests and don't mind writing extra boilerplate for edge cases, a polyfilled fetch might be enough. But for most real-world projects, Axios's out-of-the-box features save you time, reduce repetitive code, and make your HTTP logic more maintainable. Compatibility is just one piece of the puzzle—developer experience and feature completeness matter too.

内容的提问来源于stack exchange，提问作者Sasha Kos