I have some SVG files that specifies width
and height
as well as viewbox
like this:
You can reach into the embedded svg using JavaScript:
var svg = document.getElementsByTagName('object')[0].\
contentDocument.getElementsByTagName('svg')[0];
svg.removeAttribute('width');
svg.removeAttribute('height');
Since your svg already has a viewBox, Firefox should scale the 576 pixel width in the viewBox to the 400 pixel width in your document. Other svgs might benefit from a new viewBox derived from the advertised width and height (these are often the same numbers). Other browsers might benefit from different svg tweaks.