/ javascript

Generate instant previews for image upload


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:
Preview will be displayed here...