I want to test if a list of URLs is valid

I have Googled for a solution to read through a bunch of URLs, in a text file, and test if each one is valid. Anything, simple or complex, is fine. Simpler is probably better. Maybe getting a 200 response is the way to go. As I said, I tested some scripts that I found online, and non worked. Sometimes people want to see what has been tried already, but I don't think there is any sense in posting what does NOT work.

As a bonus, I'm wondering if there is a way to loop through all bookmarks in a browser, like Firefox specifically, and test if all URLs are valid or not. I'm not sure that's doable, but it would be a nice-to-have!!

TIA everyone.