1x1のGIF・PNGファイル（透過/base64）

GIF形式（39bytes）

data:image/gif;base64,R0lGODlhAQABAGAAACH5BAEKAP8ALAAAAAABAAEAAAgEAP8FBAA7
<img src="data:image/gif;base64,R0lGODlhAQABAGAAACH5BAEKAP8ALAAAAAABAAEAAAgEAP8FBAA7" alt="" height="1" width="1"> 

PNG形式（68bytes）

　

data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVQI12NgYAAAAAMAASDVlMcAAAAASUVORK5CYII=

img='data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVQI12NgYAAAAAMAASDVlMcAAAAASUVORK5CYII=';