Is Safari 17.6 still safe to use in 2025?

"Safe" connotes different meanings for different people. It's not the latest version, but even older Safari versions incorporate features unmatched by other browsers even today.

I suggest you familiarize yourself with Apple's Safari Privacy Overview. It is six years old, but no browser comes anywhere close to those privacy-centric features.

The version you are using improved upon the features described in that paper, but they are minor improvements. The security features it introduced included "locked private browsing" and improved IP address tracking prevention. Most other features are not particularly security-centric and involved various user interface and navigation changes that can't even be characterized as "improvements" as much as they are mere visual changes.

To summarize, you are already using the world's most secure browser. Using something else might be newer, but it won't be better — not as far as security is concerned.

And you will note I did not use the word "safe" because it is so commonly misused for cowing people into doing things that are ill-advised or counter to their own personal interests.

As I alluded to earlier, an answer depends on your definition of "safe". Apple provides security updates for all their products for various reasons, most of which have nothing to do with safe computing practices.