“Boop is a simple editor that allows you to execute scripts on the buffer. The idea is that you don’t have to paste potentially secret information into shady websites to do some simple transforms, like format json and decoding query strings.”
There is also a port for Linux and Windows: https://github.com/zoeyfyi/Boop-GTK
sudo install boop-gtk.linux.amd64 /usr/local/bin/boop-gtk
Run from terminal with boop-gtk