Recently, for a couple of months, I noticed that Google Search began to replace its /url?q=<encoded url> links into a more opaque one (/goto?url=<internal identifier>) randomly (indication of A/B testing) on my logged-out private browsing sessions.

The old one (intermediate link with /url?sa=...q=...) will either be presented immediately after loading the page, or after the mouse has been held down at the anchor/link (can be prevented by extensions), or not rewritten at all (maybe if something called the "anchor ping" feature is supported). The URL can be easily decoded to the intended destination, either manually (with things like URLCheck or ClearURLs), or automatically (ClearURLs, or maybe adblockers or other privacy extensions)

The newer one (/goto?url=) seems to include a seemingly random base64-encoded bytes, which I can't figure out on how to decode it back (might be an internal identifier instead of an embedded URL), except by visiting the link itself.

I suspect that they are doing this to track users more reliably, or to mitigate search results page scrapers.

What are your thoughts?