SVG Placeholder image

placeholder.svg

<svg version="1.1" xmlns="http://www.w3.org/2000/svg" width="200px" height="100px">
    <defs>
        <clipPath id="viewport">
            <rect x="0" y="0" width="100%" height="100%"/>
        </clipPath>
    </defs>
    <g clip-path="url(#viewport)">
        <rect x="0" y="0" width="100%" height="100%" stroke="black" fill="lightgray" stroke-width="2"/>
        <line x1="0" x2="100%" y1="0" y2="100%" stroke="black"/>
        <line x1="100%" x2="0" y1="0" y2="100%" stroke="black"/>
    </g>
</svg>

placeholder.svg data URI

data:image/svg+xml,%3Csvg version='1.1' xmlns='http://www.w3.org/2000/svg' width='200px' height='100px'%3E%3Cdefs%3E%3CclipPath id='viewport'%3E%3Crect x='0' y='0' width='100%25' height='100%25'/%3E%3C/clipPath%3E%3C/defs%3E%3Cg clip-path='url(%23viewport)'%3E%3Crect x='0' y='0' width='100%25' height='100%25' stroke='black' fill='lightgray' stroke-width='2'/%3E%3Cline x1='0' x2='100%25' y1='0' y2='100%25' stroke='black'/%3E%3Cline x1='100%25' x2='0' y1='0' y2='100%25' stroke='black'/%3E%3C/g%3E%3C/svg%3E