Why Axios Outperforms Fetch for Downloading Files

Why Axios Is Better Than Fetch for File Downloads

When handling file downloads, such as exporting Excel sheets, Axios often proves to be more efficient and user-friendly than Fetch due to its built-in features and streamlined syntax. Here's a breakdown of the methods and their differences.

Using Fetch to Download Files

A typical implementation using Fetch involves converting the response stream into a blob and creating a downloadable link:

function exportExcel(data) {
  fetch('https://example.com/exportExcel', {
    method: 'POST',
    body: JSON.stringify(data),
    headers: {
      'Authorization': 'Bearer xxxxxxx',
      'Content-Type': 'application/json',
    },
  })
    .then((response) => response.blob())
    .then((blob) => {
      const downloadLink = document.createElement('a');
      downloadLink.href = URL.createObjectURL(blob);
      downloadLink.download = 'file.xlsx';
      downloadLink.click();
      URL.revokeObjectURL(downloadLink.href);
    })
    .catch((error) => console.error('Download failed', error));
}

This approach requires manual conversion to a blob and careful handling of headers.

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Using Axios for Simplicity

Axios simplifies the process by directly supporting the responseType: 'blob' configuration:

function exportExcel(data) {
  axios({
    method: 'post',
    url: 'https://example.com/exportExcel',
    data: data,
    responseType: 'blob', // Automatically converts response to blob
  })
    .then((response) => {
      const downloadLink = document.createElement('a');
      downloadLink.href = URL.createObjectURL(response.data);
      downloadLink.download = 'file.xlsx';
      downloadLink.click();
      URL.revokeObjectURL(downloadLink.href);
    })
    .catch((error) => console.error('Download failed', error));
}

Advantages of Axios:

• Built-in Blob Handling: Automatically converts the response to a blob.

• Cleaner Code: Reduces boilerplate, making the implementation more concise.

• Improved Debugging: Axios provides detailed error messages for better troubleshooting.

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Key Differences Between Fetch and Axios

1. Blob Conversion: Fetch requires manual conversion to a blob, whereas Axios automatically handles this with responseType: 'blob'.

2. Ease of Use: Fetch demands more boilerplate code, while Axios simplifies implementation with built-in configurations.

3. Error Handling: Fetch offers limited native error support, but Axios provides detailed response and error objects for better debugging.

4. Headers: Headers in Fetch need to be manually configured, whereas Axios merges defaults and custom headers seamlessly.

Axios’s additional features often make it the preferred choice for complex use cases.

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Conclusion

While both Fetch and Axios can handle file downloads, Axios's built-in features make it a better choice for projects where simplicity and efficiency are essential. The configuration of responseType: 'blob' eliminates the need for manual conversions, saving time and reducing code complexity.