Terminal Hex Editors
A hex editor shows a file as raw bytes in hexadecimal beside an ASCII column, so any file can be read and changed whether or not it holds text.
In the terminal that covers hex dumps with color and grouping, editors that patch bytes in place, and viewers that decode the headers of known formats. They are used for reverse engineering, firmware and ROM work, repairing a corrupted file, and confirming what a program actually wrote to disk.
Below is a list of hex editors and byte viewers for the terminal.

fq
jq for binary formats.
jq for binary formats.

heh
A terminal UI to edit bytes by the nibble.
A terminal UI to edit bytes by the nibble.

hevi
A hex viewer.
A hex viewer.

hexabyte
A modern, modular, and robust TUI hex editor.
A modern, modular, and robust TUI hex editor.

hexapoda
A colorful modal hex editor in the terminal.
A colorful modal hex editor in the terminal.

hexhog
A configurable hex viewer/editor.
A configurable hex viewer/editor.

hexpatch
A binary patcher and editor with a terminal user interface.
A binary patcher and editor with a terminal user interface.

hexyl
A rust based command-line hex viewer
A rust based command-line hex viewer
Know any terminal tools that would be good for this list? Post a Tool here!