Preview disables clickable links in PDF files When a Mac Preview user sees a link in the PDF and tries to click it nothing happens, although the mouse cursor changes indicating that the link is clickable.

Users using other applications than Mac Preview such as Acrobat have no problems.

Does Apple Preview disable clickable links in PDF in general or is it PDF dependent?
The problem was in the encoding of the URL. Apparently Preview is more picky about that compared to other pdf viewers such as Adobe.
Also, it turns out to work better if we put the image inside the link
&lt;a ...&gt;
  &lt;img ...&gt;xx&lt;/img&gt;
&lt;/a&gt;