ToB64
ToB64 is pretty simple and easy to use. ToB64 has two very useful tools: Encoder and Decoder.

Encode allows you to convert common images to base64 code. Just pick an image from your device. Once converted it will be displayed in 3 different formats: simple base64 code, HTML code and CSS code. Finally, you can copy the results by pressing the Copy button.

Supported formats: .png, .jpg and .jpeg.

Decode allows you to convert base64 code to image. Just paste a full and valid base64 code, and press Decode. You can also save the generated image to your device.