Generate instant previews for image upload

Quick and Easy solution to generate preview of images upload in vanilla javascript in callback and Promise style.

Pankaj

Oct 9, 2017 • 1 min read

Last updated: 18 Aug 2018 • 1 min read

Hey all, I was recently working with the image upload and the problem I came across was to show the previews of the image being/to-be uploaded. After few trial-and-error attempts, I found pretty neat solution with FileReader api.

Code:

Following is the vanilla js solution for that:

And can be used in following ways:

If you are fan of Promises, you can define and use the above code in folowing ways:

Playground:

The following playground uses above callback based code. No data is sent to server.

Image:

Code:

Playground:

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