ConvertFullHalfWidth supported for sublime text 3.
It convert Full-width to Half-width or Half-width to Full-width. It Supported Katakana(kana), Alphabet(ascii) and Number(digit).
It's simple. Use Package Control.
Search ConvertFullHalfWidth
This package exclude Default.sublime-keymap.
Key map example.
[
// All Word convert to full-width.
{ "keys": ["ctrl+shift+a, ctrl+shift+"], "command": "convert_full_half_width", "args": {"to": "full", "kana": true, "ascii": true, "digit": true}},
// Katakana convert to half-width.
{ "keys": ["ctrl+shift+k, ctrl+shift+f"], "command": "convert_full_half_width", "args": {"to": "half", "kana": true}},
]