My frogs prefer the worms live. They didn't respond as well or would reject the full worms if they were cut in half. I still find that strange. I kept the bait night crawlers in the fridge and each full grown frog got one every three days or so. If I did it more frequently they didn't seem hungry and wouldn't come to a feeding. With those rear claws, if the worms were to large they would shred the worms to their manageable size. The frogs seemed to stay fat and happy so I was happy. It was always interesting to me to see those worms wiggle around in the bellies of the frogs.
Compost worms are different than other worms. A bit smaller. They do a double duty for me when I feed those in composting all my kitchen scraps and then using to feed the frogs. I would say do some reading on worm keeping if you are interested in that. It can be done pretty easily in a small space with just a few plastic containers. I use two rubbermaid totes right now.