I'd also like to see a merge feature. The proliferation of 'Reused Passwords' probably occurs as follows:
I now have 66 duplicated passwords, mostly for the same sight and it's really annoying to edit one, copy the url out, enter in one of the entries, and then delete the dup.
I'd actually prefer it if the web addresses always defaulted to a top-level domain instead of the full login URL.
That actually shouldn't happen that way, @mrtsherman. While the URL 1Password saved for a given Login item may include a fair bit more than the TLD, it should skip saving a new Login when you fill an existing one, irrespective of what exact URL you're filling on. This is something of an oversimplification, but in essence 1Password only cares about the TLD.
Now, where this can still bite you is when you sign up on TLD-A and sign in on TLD-B and copy/paste when the proper Login isn't suggested. Or any other scenario where you're signing in on a different TLD than what was saved and choose that copy/paste route. I run into this a fair bit myself with my Microsoft account since it's used across myriad services many of which don't have the same TLD that was originally associated with my Login item. I'm also impatient sometimes so I copy/paste rather than updating my Login item like I should. And, of course, allowing 1Password to save things is reflex at this point so I've duped myself a few times. Interestingly enough, that's one reason that just saving the TLD isn't a great solution here. You'd find yourself in the same situation in the above scenario, TLD only or not.
With that said, I'd be curious how you did end up with these duplicates. As I mentioned, 1Password should never save something it filled. It knows that Login item already exists and nothing has changes so it has no cause to save and doesn't care about the exact URL. Are all of these duplicates using the same TLD? Are they perhaps in different vaults or accounts? Maybe saved on different devices that weren't syncing properly? While a duplicate merge tool would be most excellent, I think the better solution for you is to figure out why this is happening. By my read, it shouldn't be, which means we should be able to fix it.
Please prioritize merge feature. Been requested by many people over the years. Just look at Google merge contacts feature (select what to keep in a side-by-side view). I don't see any reason why this shouldn't be possible with 1Password. It's tiring reading about theoretical excuses that usually derives from wrong assumptions about what is asked.
Thank you for your feedback on this as well @Mikrdk!