How to Convert a Blob to Base64 String in Node.js Without Size Loss

Описание: Learn how to accurately convert `Blob` to `Base64` and back in Node.js without changing size, ensuring data integrity throughout the process.
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This video is based on the question https://stackoverflow.com/q/75694107/ asked by the user 'NewToCode' ( https://stackoverflow.com/u/20158567/ ) and on the answer https://stackoverflow.com/a/75697477/ provided by the user 'NewToCode' ( https://stackoverflow.com/u/20158567/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Understanding the Blob to Base64 Conversion Challenge in Node.js

When working with data processing in Node.js, especially when dealing with binary data such as files or images, you might encounter a common issue: converting a Blob to a Base64 string and then back to a Blob results in a difference in size. This leads to concerns about data integrity and may seem frustrating when you want the original Blob back unchanged.

In this post, we will explore this issue and provide a solution to ensure that the conversion between Blob and Base64 string does not alter your data. Let’s dive into the problem and the solution we can implement in our Node.js applications.

The Problem Explained

When you convert a Blob to a Base64 string and then attempt to recreate the Blob from that string, you may notice discrepancies in the size of the resulting Blob. Here’s the typical code pattern you might use:

[[See Video to Reveal this Text or Code Snippet]]

In this scenario, even if the outputs in the console appear visually similar, the sizes of the original and reconstructed Blob objects may vary. This inconsistency can complicate tasks that rely on exact replica of data.

The Solution: Ensuring Consistent Blob Size

Step 1: Use ArrayBuffer instead of text() Method

Instead of converting the Blob to a text string, which can lead to issues, utilize the ArrayBuffer method to get a more accurate representation of the binary data. Here's how you can do this:

[[See Video to Reveal this Text or Code Snippet]]

This method captures the binary data effectively without altering its structure.

Step 2: Convert to JSON Buffer (if required)

If you plan to store or transmit data in formatted ways such as JSON, you may need to convert your buffer into a JSON format. This is done using the following line of code:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Constructing the Blob from the JSON Buffer

Finally, to reconstruct the Blob, you will convert the JSON buffer back into a Blob:

[[See Video to Reveal this Text or Code Snippet]]

This new Blob should correctly represent your original Blob, retaining the same data size and characteristics.

Conclusion

Using the above method, you can now safely and accurately convert a Blob to a Base64 string and then back to a Blob without losing data or having discrepancies in size. Remember, leveraging ArrayBuffer is key to maintaining data integrity through the conversion process.

With this information, you can enhance your Node.js applications to handle binary data more efficiently, ensuring that your data remains intact through conversions. Happy coding!