Differences from

Vim

Helix's editing model is strongly inspired from vim and kakoune, and a notable difference from vim (and the most striking similarity to kakoune) is that Helix follows the selection → action model. This means that whatever you are going to act on (a word, a paragraph, a line, etc) is selected first and the action itself (delete, change, yank, etc) comes second. A cursor is simply a single width selection.

Kakoune

Helix has a extend mode (v like vim) to prevent holding shift to extend and not being able to extend in cases like page up/down in kakoune.