The main draw of HextEdit is the UI, it was designed to fit in with Big Sur, whereas Hex Fiend has some issues with elements cut off. They have similar feature sets, Hex Fiend has the added benefit of a diffing view, but I hope to add some more advanced features in the coming versions. I think HextEdit has some nice unique features that are expected of modern macOS apps, like version history and dark mode. They're both quite simple hex editors, and are both free!
What kind of things are you doing w binary data where an editor like this comes in handy?
For example reverse engineering and parsing binary file formats
Same Q. I love HexFiend. It’s saved my bacon many times.