Google is testing a new visual treatment for sitelinks in Search ads on desktop. When users hover over sitelinks, the link text now appears underlined, mimicking standard hyperlink behavior seen across the web, and with light grey background.

The change is subtle but could improve user clarity and engagement with sitelinks, which often lead to important secondary pages.
Sitelinks are a key part of ad real estate, so even minor formatting tweaks can impact click behavior and user perception.
This update was spotted by Hana Kobzová.