Resize Google Maps marker icon image

If the original size is 100 x 100 and you want to scale it to 50 x 50, use scaledSize instead of Size.

const icon = {
    url: "../res/sit_marron.png", // url
    scaledSize: new google.maps.Size(50, 50), // scaled size
    origin: new google.maps.Point(0,0), // origin
    anchor: new google.maps.Point(0, 0) // anchor
};

const marker = new google.maps.Marker({
    position: new google.maps.LatLng(lat, lng),
    map: map,
    icon: icon
});