Everytime I needed to decode or encode something with base64 I looked up the first website on Google and was mad about all the ads and the non-intuitive interface of the website. This is why I choose to create a really simple base64 de/encoder without any ads and with a clean interface.
For the base64 encoding I’ve used the jQuery plugin jquery-base64. This may seem like a overkill and it probably is, but at the time I was looking for a short and sweet solution without having to implement the base64 encoding myself. The rest is just simply listening for click on the button and then using the plugin to en/decode the values in the textareas and displaying them.
At the time I was still learning how to correctly use jQuery and had some problems registering the onclick callbacks for the buttons.