The gradientUnits read-only property of the SVGGradientElement interface reflects the gradientUnits attribute of the given element. It takes one of the SVG_UNIT_TYPE_* constants defined in SVGUnitTypes.
gradientUnits property<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200">
<defs>
<linearGradient id="gradient1" gradientUnits="userSpaceOnUse">
<stop offset="0%" stop-color="red" />
<stop offset="100%" stop-color="blue" />
</linearGradient>
</defs>
<rect x="10" y="10" width="180" height="180" fill="url(#gradient1)" />
</svg>const gradient = document.getElementById("gradient1");
console.log(gradient.gradientUnits.baseVal); // Output: 1 (SVG_UNIT_TYPE_USERSPACEONUSE)