Are old hotels still asking for credit card details when booking - is it safe?

When I book at old hotels, the same thing happens to me, and honestly it really depends on how they handle that data. If the site has HTTPS (you see the little padlock in the address bar) and looks legitimate, it's usually fine, but the ideal thing is to call them up and give your card details over the phone instead of typing them into an old form. A lot of smaller hotels still haven't updated their systems, but that doesn't mean they're insecure - what matters is that they don't share your information with third parties or leave it saved on an unprotected server.