Is it better to convert money in the US or abroad?

Hey there, I'm curious about something. When it comes to converting money, is it more advantageous to do it in the US or abroad? I've heard differing opinions on this, and I'm trying to weigh the pros and cons. For example, I'm considering traveling abroad soon and need to convert some of my dollars into the local currency. Should I do it before I leave the US, or should I wait until I get there? I'm wondering if there are any hidden fees or better exchange rates to be aware of. What's your take on this?