Yes, beagles are good with cats. Although this breed was originally bred to sniff out prey, they have no particular dislike of cats.
If they spot a cat outside, instinct may take over and they’ll chase it. However, inside the house, they’ll treat cats gently. If they do chase, it will only be as part of a game, with no intention to hurt. And afterward, they’ll happily cuddle up with any feline family member for a cozy nap.
Having said that, if you’re introducing a cat into a home with a beagle, take care to introduce them to each other gradually, and let them both get comfortable with their new companion. When you’re 100% sure that they understand the rules of this new relationship, you can happily leave them alone to enjoy each other’s company.